<informationTable xmlns="http://www.sec.gov/edgar/document/thirteenf/informationtable">		<infoTable>
			<nameOfIssuer>ABENGOA YIELD PLC</nameOfIssuer>
			<titleOfClass>ORD SHS</titleOfClass>
			<cusip>G00349103</cusip>
			<value>1551</value>
			<shrsOrPrnAmt>
				<sshPrnamt>45900</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>45900</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ACUITY BRANDS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>00508Y102</cusip>
			<value>5</value>
			<shrsOrPrnAmt>
				<sshPrnamt>27</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>27</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>AMERICAN WTR WKS CO INC NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>030420103</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>23</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>23</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ANADARKO PETE CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>032511107</cusip>
			<value>34994</value>
			<shrsOrPrnAmt>
				<sshPrnamt>422578</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>422578</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ANTERO MIDSTREAM PARTNERS LP</nameOfIssuer>
			<titleOfClass>UNT LTD PARTN</titleOfClass>
			<cusip>03673L103</cusip>
			<value>182318</value>
			<shrsOrPrnAmt>
				<sshPrnamt>7536924</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>6858060</Sole>
				<Shared>0</Shared>
				<None>678864</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ANTERO RES CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>03674X106</cusip>
			<value>6820</value>
			<shrsOrPrnAmt>
				<sshPrnamt>193090</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>193090</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>APACHE CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>037411105</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>14</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>14</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>AQUA AMERICA INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>03836W103</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>38</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>38</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ASPEN AEROGELS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>04523Y105</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>69</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>69</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>BAKER HUGHES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>057224107</cusip>
			<value>1879</value>
			<shrsOrPrnAmt>
				<sshPrnamt>29555</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>29555</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>BIOAMBER INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>09072Q106</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>58</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>58</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>BP PLC</nameOfIssuer>
			<titleOfClass>SPONSORED ADR</titleOfClass>
			<cusip>055622104</cusip>
			<value>3770</value>
			<shrsOrPrnAmt>
				<sshPrnamt>96400</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>96400</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>BUCKEYE PARTNERS L P</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>118230101</cusip>
			<value>812832</value>
			<shrsOrPrnAmt>
				<sshPrnamt>10763141</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>9937205</Sole>
				<Shared>0</Shared>
				<None>825936</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>C&amp;J ENERGY SVCS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>12467B304</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>89</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>89</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CABOT OIL &amp; GAS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>127097103</cusip>
			<value>8780</value>
			<shrsOrPrnAmt>
				<sshPrnamt>297324</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>297324</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CALPINE CORP</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>131347304</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>50</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>50</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CAMERON INTERNATIONAL CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>13342B105</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>22</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>22</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CANADIAN SOLAR INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>136635109</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>33</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>33</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CARRIZO OIL &amp; GAS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>144577103</cusip>
			<value>11164</value>
			<shrsOrPrnAmt>
				<sshPrnamt>224846</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>224846</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CENOVUS ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>15135U109</cusip>
			<value>2586</value>
			<shrsOrPrnAmt>
				<sshPrnamt>153200</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>153200</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CENTERPOINT ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>15189T107</cusip>
			<value>5169</value>
			<shrsOrPrnAmt>
				<sshPrnamt>253253</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>253253</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CHART INDS INC</nameOfIssuer>
			<titleOfClass>COM PAR $0.01</titleOfClass>
			<cusip>16115Q308</cusip>
			<value>0</value>
			<shrsOrPrnAmt>
				<sshPrnamt>11</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>11</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CHENIERE ENERGY INC</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>16411R208</cusip>
			<value>44406</value>
			<shrsOrPrnAmt>
				<sshPrnamt>573727</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>573727</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CHESAPEAKE ENERGY CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>165167107</cusip>
			<value>4089</value>
			<shrsOrPrnAmt>
				<sshPrnamt>288802</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>288802</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CHEVRON CORP NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>166764100</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>18</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>18</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CIMAREX ENERGY CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>171798101</cusip>
			<value>14370</value>
			<shrsOrPrnAmt>
				<sshPrnamt>124859</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>124859</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CMS ENERGY CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>125896100</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>49</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>49</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>COLUMBIA PIPELINE PARTNERS L</nameOfIssuer>
			<titleOfClass>COM UT REPSTG</titleOfClass>
			<cusip>198281107</cusip>
			<value>165935</value>
			<shrsOrPrnAmt>
				<sshPrnamt>5992596</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>5576143</Sole>
				<Shared>0</Shared>
				<None>416453</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CONCHO RES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>20605P101</cusip>
			<value>17506</value>
			<shrsOrPrnAmt>
				<sshPrnamt>151017</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>151017</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CONOCOPHILLIPS</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>20825C104</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>28</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>28</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CONTINENTAL RESOURCES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>212015101</cusip>
			<value>8420</value>
			<shrsOrPrnAmt>
				<sshPrnamt>192810</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>192810</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>CORE LABORATORIES N V</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>N22717107</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>8</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>8</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DCP MIDSTREAM PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UT LTD PTN</titleOfClass>
			<cusip>23311P100</cusip>
			<value>364530</value>
			<shrsOrPrnAmt>
				<sshPrnamt>9865502</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>9120065</Sole>
				<Shared>0</Shared>
				<None>745437</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DEVON ENERGY CORP NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>25179M103</cusip>
			<value>7936</value>
			<shrsOrPrnAmt>
				<sshPrnamt>131588</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>131588</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DHT HOLDINGS INC</nameOfIssuer>
			<titleOfClass>SHS NEW</titleOfClass>
			<cusip>Y2065G121</cusip>
			<value>224</value>
			<shrsOrPrnAmt>
				<sshPrnamt>32134</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>32134</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DIAMONDBACK ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>25278X109</cusip>
			<value>1094</value>
			<shrsOrPrnAmt>
				<sshPrnamt>14243</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>14243</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DOMINION MIDSTREAM PARTNERS</nameOfIssuer>
			<titleOfClass>COM UT REP LTD</titleOfClass>
			<cusip>257454108</cusip>
			<value>109294</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2632965</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>2465930</Sole>
				<Shared>0</Shared>
				<None>167035</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DOMINION RES INC VA NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>25746U109</cusip>
			<value>5</value>
			<shrsOrPrnAmt>
				<sshPrnamt>70</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>70</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DORIAN LPG LTD</nameOfIssuer>
			<titleOfClass>SHS USD</titleOfClass>
			<cusip>Y2106R110</cusip>
			<value>1164</value>
			<shrsOrPrnAmt>
				<sshPrnamt>89348</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>89348</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DRIL-QUIP INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>262037104</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>12</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>12</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>DTE ENERGY CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>233331107</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>29</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>29</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EASTMAN CHEM CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>277432100</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>17</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>17</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EDISON INTL</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>281020107</cusip>
			<value>4</value>
			<shrsOrPrnAmt>
				<sshPrnamt>58</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>58</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EMERGE ENERGY SVCS LP</nameOfIssuer>
			<titleOfClass>COM REP PARTN</titleOfClass>
			<cusip>29102H108</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>24</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>24</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENBRIDGE ENERGY MANAGEMENT L</nameOfIssuer>
			<titleOfClass>SHS UNITS LLI</titleOfClass>
			<cusip>29250X103</cusip>
			<value>53672</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1475321</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>1475321</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENBRIDGE ENERGY PARTNERS L P</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>29250R106</cusip>
			<value>568326</value>
			<shrsOrPrnAmt>
				<sshPrnamt>15782442</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>14615607</Sole>
				<Shared>0</Shared>
				<None>1166835</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENBRIDGE INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>29250N105</cusip>
			<value>188000</value>
			<shrsOrPrnAmt>
				<sshPrnamt>3876287</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>3876287</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENCANA CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>292505104</cusip>
			<value>3461</value>
			<shrsOrPrnAmt>
				<sshPrnamt>310380</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>310380</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENERGEN CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>29265N108</cusip>
			<value>5551</value>
			<shrsOrPrnAmt>
				<sshPrnamt>84112</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>84112</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENERGY TRANSFER EQUITY L P</nameOfIssuer>
			<titleOfClass>COM UT LTD PTN</titleOfClass>
			<cusip>29273V100</cusip>
			<value>905328</value>
			<shrsOrPrnAmt>
				<sshPrnamt>14288640</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>12723439</Sole>
				<Shared>0</Shared>
				<None>1565201</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENERGY TRANSFER PRTNRS L P</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>29273R109</cusip>
			<value>361613</value>
			<shrsOrPrnAmt>
				<sshPrnamt>6486326</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>6486326</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENERPLUS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>292766102</cusip>
			<value>2797</value>
			<shrsOrPrnAmt>
				<sshPrnamt>275800</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>275800</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENLINK MIDSTREAM PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT REP LTD</titleOfClass>
			<cusip>29336U107</cusip>
			<value>192369</value>
			<shrsOrPrnAmt>
				<sshPrnamt>7775615</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>7407892</Sole>
				<Shared>0</Shared>
				<None>367723</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENLINK MIDSTREAM LLC</nameOfIssuer>
			<titleOfClass>COM UNIT REP LTD</titleOfClass>
			<cusip>29336T100</cusip>
			<value>38113</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1171251</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>1171251</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENPHASE ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>29355A107</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>112</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>112</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ENTERPRISE PRODS PARTNERS L</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>293792107</cusip>
			<value>1261759</value>
			<shrsOrPrnAmt>
				<sshPrnamt>38316400</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>35148255</Sole>
				<Shared>0</Shared>
				<None>3168145</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EOG RES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>26875P101</cusip>
			<value>43152</value>
			<shrsOrPrnAmt>
				<sshPrnamt>470624</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>470624</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EP ENERGY CORP</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>268785102</cusip>
			<value>2118</value>
			<shrsOrPrnAmt>
				<sshPrnamt>202065</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>202065</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EQT CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>26884L109</cusip>
			<value>23446</value>
			<shrsOrPrnAmt>
				<sshPrnamt>282931</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>282931</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EQT MIDSTREAM PARTNERS LP</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>26885B100</cusip>
			<value>452519</value>
			<shrsOrPrnAmt>
				<sshPrnamt>5826924</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>5364832</Sole>
				<Shared>0</Shared>
				<None>462092</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EXTERRAN HLDGS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>30225X103</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>24</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>24</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>EXXON MOBIL CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>30231G102</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>15</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>15</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FIRST SOLAR INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>336433107</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>40</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>40</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FLUOR CORP NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>343412102</cusip>
			<value>0</value>
			<shrsOrPrnAmt>
				<sshPrnamt>4</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>4</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FMC TECHNOLOGIES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>30249U101</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>32</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>32</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FMSA HLDGS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>30255X106</cusip>
			<value>0</value>
			<shrsOrPrnAmt>
				<sshPrnamt>51</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>51</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FORUM ENERGY TECHNOLOGIES IN</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>34984V100</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>41</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>41</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>FRANKS INTL N V</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>N33462107</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>53</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>53</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>GENESIS ENERGY L P</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>371927104</cusip>
			<value>208220</value>
			<shrsOrPrnAmt>
				<sshPrnamt>4430215</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>3948246</Sole>
				<Shared>0</Shared>
				<None>481969</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HALLIBURTON CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>406216101</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>17</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>17</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HELMERICH &amp; PAYNE INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>423452101</cusip>
			<value>433</value>
			<shrsOrPrnAmt>
				<sshPrnamt>6360</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>6360</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HESS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>42809H107</cusip>
			<value>3395</value>
			<shrsOrPrnAmt>
				<sshPrnamt>50028</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>50028</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HOEGH LNG PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT LTD</titleOfClass>
			<cusip>Y3262R100</cusip>
			<value>1040</value>
			<shrsOrPrnAmt>
				<sshPrnamt>47934</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>47934</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HOLLY ENERGY PARTNERS L P</nameOfIssuer>
			<titleOfClass>COM UT LTD PTN</titleOfClass>
			<cusip>435763107</cusip>
			<value>97114</value>
			<shrsOrPrnAmt>
				<sshPrnamt>3088876</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>3088876</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>HOLLYFRONTIER CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>436106108</cusip>
			<value>894</value>
			<shrsOrPrnAmt>
				<sshPrnamt>22195</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>22195</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>INFRAREIT INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>45685L100</cusip>
			<value>5282</value>
			<shrsOrPrnAmt>
				<sshPrnamt>184751</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>184751</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ITC HLDGS CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>465685105</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>25</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>25</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ITRON INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>465741106</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>40</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>40</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>KINDER MORGAN INC DEL</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>49456B101</cusip>
			<value>250866</value>
			<shrsOrPrnAmt>
				<sshPrnamt>5964491</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>5964491</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>LAREDO PETROLEUM INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>516806106</cusip>
			<value>4238</value>
			<shrsOrPrnAmt>
				<sshPrnamt>325034</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>325034</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>LYONDELLBASELL INDUSTRIES N</nameOfIssuer>
			<titleOfClass>SHS - A -</titleOfClass>
			<cusip>N53745100</cusip>
			<value>2473</value>
			<shrsOrPrnAmt>
				<sshPrnamt>28170</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>28170</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MAGELLAN MIDSTREAM PRTNRS LP</nameOfIssuer>
			<titleOfClass>COM UNIT RP LP</titleOfClass>
			<cusip>559080106</cusip>
			<value>1255074</value>
			<shrsOrPrnAmt>
				<sshPrnamt>16361289</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>15000535</Sole>
				<Shared>0</Shared>
				<None>1360754</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MARATHON OIL CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>565849106</cusip>
			<value>16262</value>
			<shrsOrPrnAmt>
				<sshPrnamt>622836</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>622836</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MARATHON PETE CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>56585A102</cusip>
			<value>1118</value>
			<shrsOrPrnAmt>
				<sshPrnamt>10922</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>10922</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MARKWEST ENERGY PARTNERS L P</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>570759100</cusip>
			<value>752757</value>
			<shrsOrPrnAmt>
				<sshPrnamt>11388160</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>10572092</Sole>
				<Shared>0</Shared>
				<None>816068</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MAXWELL TECHNOLOGIES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>577767106</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>122</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>122</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>MPLX LP</nameOfIssuer>
			<titleOfClass>COM UNIT REP LTD</titleOfClass>
			<cusip>55336V100</cusip>
			<value>421565</value>
			<shrsOrPrnAmt>
				<sshPrnamt>5754374</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>5299095</Sole>
				<Shared>0</Shared>
				<None>455279</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NABORS INDUSTRIES LTD</nameOfIssuer>
			<titleOfClass>SHS</titleOfClass>
			<cusip>G6359F103</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>100</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>100</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NATIONAL FUEL GAS CO N J</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>636180101</cusip>
			<value>27916</value>
			<shrsOrPrnAmt>
				<sshPrnamt>462729</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>462729</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NATIONAL OILWELL VARCO INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>637071101</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>23</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>23</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NEWFIELD EXPL CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>651290108</cusip>
			<value>11971</value>
			<shrsOrPrnAmt>
				<sshPrnamt>341161</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>341161</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NEWPARK RES INC</nameOfIssuer>
			<titleOfClass>COM PAR $.01NEW</titleOfClass>
			<cusip>651718504</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>68</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>68</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NEXTERA ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>65339F101</cusip>
			<value>6</value>
			<shrsOrPrnAmt>
				<sshPrnamt>62</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>62</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NEXTERA ENERGY PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT PART IN</titleOfClass>
			<cusip>65341B106</cusip>
			<value>4573</value>
			<shrsOrPrnAmt>
				<sshPrnamt>104359</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>104359</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NISOURCE INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>65473P105</cusip>
			<value>210391</value>
			<shrsOrPrnAmt>
				<sshPrnamt>4764281</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>4764281</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NOBLE ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>655044105</cusip>
			<value>13145</value>
			<shrsOrPrnAmt>
				<sshPrnamt>268822</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>268822</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NORDIC AMERICAN TANKERS LIMI</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>G65773106</cusip>
			<value>254</value>
			<shrsOrPrnAmt>
				<sshPrnamt>21323</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>21323</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NRG ENERGY INC</nameOfIssuer>
			<titleOfClass>COM NEW</titleOfClass>
			<cusip>629377508</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>64</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>64</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NRG YIELD INC</nameOfIssuer>
			<titleOfClass>COM CL A</titleOfClass>
			<cusip>62942X108</cusip>
			<value>5333</value>
			<shrsOrPrnAmt>
				<sshPrnamt>105129</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>105129</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>NUSTAR ENERGY LP</nameOfIssuer>
			<titleOfClass>UNIT COM</titleOfClass>
			<cusip>67058H102</cusip>
			<value>83896</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1382134</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>1382134</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>OCCIDENTAL PETE CORP DEL</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>674599105</cusip>
			<value>17046</value>
			<shrsOrPrnAmt>
				<sshPrnamt>233501</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>233501</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ONE GAS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>68235P108</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>53</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>53</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ONEOK PARTNERS LP</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>68268N103</cusip>
			<value>301040</value>
			<shrsOrPrnAmt>
				<sshPrnamt>7371199</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>7371199</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ONEOK INC NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>682680103</cusip>
			<value>360885</value>
			<shrsOrPrnAmt>
				<sshPrnamt>7481035</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>6796525</Sole>
				<Shared>0</Shared>
				<None>684510</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PATTERN ENERGY GROUP INC</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>70338P100</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>80</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>80</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PATTERSON UTI ENERGY INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>703481101</cusip>
			<value>225</value>
			<shrsOrPrnAmt>
				<sshPrnamt>11999</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>11999</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PEMBINA PIPELINE CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>706327103</cusip>
			<value>56131</value>
			<shrsOrPrnAmt>
				<sshPrnamt>1776441</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>1776441</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PENN WEST PETE LTD NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>707887105</cusip>
			<value>11</value>
			<shrsOrPrnAmt>
				<sshPrnamt>6400</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>6400</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PHILLIPS 66</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>718546104</cusip>
			<value>2339</value>
			<shrsOrPrnAmt>
				<sshPrnamt>29764</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>29764</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PHILLIPS 66 PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT REP INT</titleOfClass>
			<cusip>718549207</cusip>
			<value>267507</value>
			<shrsOrPrnAmt>
				<sshPrnamt>3785301</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>3462749</Sole>
				<Shared>0</Shared>
				<None>322552</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PINNACLE WEST CAP CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>723484101</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>15</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>15</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PIONEER NAT RES CO</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>723787107</cusip>
			<value>38977</value>
			<shrsOrPrnAmt>
				<sshPrnamt>238378</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>238378</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PLAINS ALL AMERN PIPELINE L</nameOfIssuer>
			<titleOfClass>UNIT LTD PARTN</titleOfClass>
			<cusip>726503105</cusip>
			<value>1219947</value>
			<shrsOrPrnAmt>
				<sshPrnamt>25014285</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>23101379</Sole>
				<Shared>0</Shared>
				<None>1912906</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PLAINS GP HLDGS L P</nameOfIssuer>
			<titleOfClass>SHS A REP LTPN</titleOfClass>
			<cusip>72651A108</cusip>
			<value>242465</value>
			<shrsOrPrnAmt>
				<sshPrnamt>8546537</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>8002933</Sole>
				<Shared>0</Shared>
				<None>543604</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>POLYPORE INTL INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>73179V103</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>42</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>42</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PPL CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>69351T106</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>70</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>70</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>PRECISION DRILLING CORP</nameOfIssuer>
			<titleOfClass>COM 2010</titleOfClass>
			<cusip>74022D308</cusip>
			<value>0</value>
			<shrsOrPrnAmt>
				<sshPrnamt>40</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>40</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>QEP RES INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>74733V100</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>56</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>56</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>QUESTAR CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>748356102</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>25</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>25</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>RANGE RES CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>75281A109</cusip>
			<value>15089</value>
			<shrsOrPrnAmt>
				<sshPrnamt>289956</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>289956</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>REGENCY ENERGY PARTNERS L P</nameOfIssuer>
			<titleOfClass>COM UNITS L P</titleOfClass>
			<cusip>75885Y107</cusip>
			<value>305718</value>
			<shrsOrPrnAmt>
				<sshPrnamt>13367638</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>12999658</Sole>
				<Shared>0</Shared>
				<None>367980</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ROSE ROCK MIDSTREAM L P</nameOfIssuer>
			<titleOfClass>COM U REP LTD</titleOfClass>
			<cusip>777149105</cusip>
			<value>1543</value>
			<shrsOrPrnAmt>
				<sshPrnamt>32489</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>32489</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>ROYAL DUTCH SHELL PLC</nameOfIssuer>
			<titleOfClass>SPONS ADR A</titleOfClass>
			<cusip>780259206</cusip>
			<value>6830</value>
			<shrsOrPrnAmt>
				<sshPrnamt>114500</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>114500</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>RPC INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>749660106</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>68</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>68</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>RSP PERMIAN INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>74978Q105</cusip>
			<value>3037</value>
			<shrsOrPrnAmt>
				<sshPrnamt>120559</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>120559</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SCHLUMBERGER LTD</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>806857108</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>29</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>29</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SEMGROUP CORP</nameOfIssuer>
			<titleOfClass>CL A</titleOfClass>
			<cusip>81663A105</cusip>
			<value>47594</value>
			<shrsOrPrnAmt>
				<sshPrnamt>585123</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>585123</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SEMPRA ENERGY</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>816851109</cusip>
			<value>5</value>
			<shrsOrPrnAmt>
				<sshPrnamt>49</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>49</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SHELL MIDSTREAM PARTNERS L P</nameOfIssuer>
			<titleOfClass>UNIT LTD INT</titleOfClass>
			<cusip>822634101</cusip>
			<value>192133</value>
			<shrsOrPrnAmt>
				<sshPrnamt>4926479</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>4545493</Sole>
				<Shared>0</Shared>
				<None>380986</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SOLARCITY CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>83416T100</cusip>
			<value>6</value>
			<shrsOrPrnAmt>
				<sshPrnamt>112</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>112</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SPECTRA ENERGY CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>847560109</cusip>
			<value>456292</value>
			<shrsOrPrnAmt>
				<sshPrnamt>12615217</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>11737409</Sole>
				<Shared>0</Shared>
				<None>877808</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SPECTRA ENERGY PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>84756N109</cusip>
			<value>532615</value>
			<shrsOrPrnAmt>
				<sshPrnamt>10284121</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>9760598</Sole>
				<Shared>0</Shared>
				<None>523523</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SUMMIT MIDSTREAM PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT LTD</titleOfClass>
			<cusip>866142102</cusip>
			<value>17133</value>
			<shrsOrPrnAmt>
				<sshPrnamt>532573</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>532573</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SUNCOR ENERGY INC NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>867224107</cusip>
			<value>14931</value>
			<shrsOrPrnAmt>
				<sshPrnamt>510456</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>510456</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SUNEDISON INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>86732Y109</cusip>
			<value>5</value>
			<shrsOrPrnAmt>
				<sshPrnamt>228</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>228</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SUNOCO LOGISTICS PRTNRS L P</nameOfIssuer>
			<titleOfClass>COM UNITS</titleOfClass>
			<cusip>86764L108</cusip>
			<value>764253</value>
			<shrsOrPrnAmt>
				<sshPrnamt>18487016</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>17053890</Sole>
				<Shared>0</Shared>
				<None>1433126</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SUNPOWER CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>867652406</cusip>
			<value>5</value>
			<shrsOrPrnAmt>
				<sshPrnamt>174</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>174</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>SUPERIOR ENERGY SVCS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>868157108</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>45</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>45</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TARGA RESOURCES PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT</titleOfClass>
			<cusip>87611X105</cusip>
			<value>201636</value>
			<shrsOrPrnAmt>
				<sshPrnamt>4875134</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>4875134</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TARGA RES CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>87612G101</cusip>
			<value>291662</value>
			<shrsOrPrnAmt>
				<sshPrnamt>3044811</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>2741119</Sole>
				<Shared>0</Shared>
				<None>303692</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TEEKAY OFFSHORE PARTNERS L P</nameOfIssuer>
			<titleOfClass>PARTNERSHIP UN</titleOfClass>
			<cusip>Y8565J101</cusip>
			<value>4714</value>
			<shrsOrPrnAmt>
				<sshPrnamt>223330</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>223330</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TERRAFORM PWR INC</nameOfIssuer>
			<titleOfClass>CL A COM</titleOfClass>
			<cusip>88104R100</cusip>
			<value>9628</value>
			<shrsOrPrnAmt>
				<sshPrnamt>266446</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>266446</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TESLA MTRS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>88160R101</cusip>
			<value>5</value>
			<shrsOrPrnAmt>
				<sshPrnamt>28</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>28</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TESORO LOGISTICS LP</nameOfIssuer>
			<titleOfClass>COM UNIT LP</titleOfClass>
			<cusip>88160T107</cusip>
			<value>450912</value>
			<shrsOrPrnAmt>
				<sshPrnamt>8381269</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>7697112</Sole>
				<Shared>0</Shared>
				<None>684157</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TETRA TECHNOLOGIES INC DEL</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>88162F105</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>81</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>81</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>TRANSCANADA CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>89353D107</cusip>
			<value>123615</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2893617</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>2893617</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>U S SILICA HLDGS INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>90346E103</cusip>
			<value>1065</value>
			<shrsOrPrnAmt>
				<sshPrnamt>29915</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>29915</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>VALERO ENERGY CORP NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>91913Y100</cusip>
			<value>2333</value>
			<shrsOrPrnAmt>
				<sshPrnamt>36672</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>36672</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>VALERO ENERGY PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNT REP LP</titleOfClass>
			<cusip>91914J102</cusip>
			<value>173463</value>
			<shrsOrPrnAmt>
				<sshPrnamt>3583954</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>3285135</Sole>
				<Shared>0</Shared>
				<None>298819</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>VTTI ENERGY PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT RP LT</titleOfClass>
			<cusip>Y9384M101</cusip>
			<value>13236</value>
			<shrsOrPrnAmt>
				<sshPrnamt>533299</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>533299</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WEATHERFORD INTL PLC</nameOfIssuer>
			<titleOfClass>ORD SHS</titleOfClass>
			<cusip>G48833100</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>110</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>110</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WESTERN GAS EQUITY PARTNERS</nameOfIssuer>
			<titleOfClass>COMUNT LTD PT</titleOfClass>
			<cusip>95825R103</cusip>
			<value>132723</value>
			<shrsOrPrnAmt>
				<sshPrnamt>2212058</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>1940523</Sole>
				<Shared>0</Shared>
				<None>271535</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WESTERN GAS PARTNERS LP</nameOfIssuer>
			<titleOfClass>COM UNIT LP IN</titleOfClass>
			<cusip>958254104</cusip>
			<value>565319</value>
			<shrsOrPrnAmt>
				<sshPrnamt>8584950</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>7968745</Sole>
				<Shared>0</Shared>
				<None>616205</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WESTERN REFNG INC</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>959319104</cusip>
			<value>1</value>
			<shrsOrPrnAmt>
				<sshPrnamt>27</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>27</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WESTLAKE CHEM CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>960413102</cusip>
			<value>1847</value>
			<shrsOrPrnAmt>
				<sshPrnamt>25676</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>25676</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WHITING PETE CORP NEW</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>966387102</cusip>
			<value>4918</value>
			<shrsOrPrnAmt>
				<sshPrnamt>159174</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>159174</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WILLIAMS COS INC DEL</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>969457100</cusip>
			<value>402427</value>
			<shrsOrPrnAmt>
				<sshPrnamt>7954667</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>7497663</Sole>
				<Shared>0</Shared>
				<None>457004</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WILLIAMS PARTNERS L P</nameOfIssuer>
			<titleOfClass>COM UNIT L P</titleOfClass>
			<cusip>96950F104</cusip>
			<value>313750</value>
			<shrsOrPrnAmt>
				<sshPrnamt>6374444</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>6374444</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
		<infoTable>
			<nameOfIssuer>WISCONSIN ENERGY CORP</nameOfIssuer>
			<titleOfClass>COM</titleOfClass>
			<cusip>976657106</cusip>
			<value>2</value>
			<shrsOrPrnAmt>
				<sshPrnamt>47</sshPrnamt>
				<sshPrnamtType>SH</sshPrnamtType>
			</shrsOrPrnAmt>
			<investmentDiscretion>SOLE</investmentDiscretion>
			<otherManager>N/A</otherManager>
			<votingAuthority>
				<Sole>47</Sole>
				<Shared>0</Shared>
				<None>0</None>
			</votingAuthority>
		</infoTable>
</informationTable>
