UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED
MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number: 811-06292
______________________________________________

UBS Investment Trust
______________________________________________________________________________

(Exact name of registrant as specified in charter)

1285 Avenue of the Americas, New York, New York 10019-6028
______________________________________________________________________________
(Address of principal executive offices) (Zip code)

Mark F. Kemper, Esq.
UBS Global Asset Management
1285 Avenue of the Americas
New York, NY 10019-6028
(Name and address of agent for service)

Copy to:
Jack W. Murphy, Esq.
Dechert LLP
1775 I Street, N.W.
Washington, DC 20006-2401

Registrant’s telephone number, including area code: 212-821 3000

Date of fiscal year end: August  31

Date of reporting period: May  31, 2012

Item 1. Schedule of Investments

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — 53.40%
Aerospace & defense — 1.53%
BE Aerospace, Inc. *	1,800	77,975
General Dynamics Corp.	16,300	1,043,363
LMI Aerospace, Inc. *	2,600	40,820
The Boeing Co.	13,100	911,891
United Technologies Corp.	25,900	1,919,449
		3,993,498
Air freight & logistics — 0.02%
Hub Group, Inc., Class A *	1,800	62,928
Auto components — 0.45%
Johnson Controls, Inc.	35,500	1,069,970
Tenneco, Inc. *	4,100	111,315
		1,181,285
Automobiles — 0.35%
General Motors Co. *	40,500	899,100
Beverages — 0.13%
Monster Beverage Corp. *	4,500	326,700
National Beverage Corp. *	256	3,702
		330,402
Biotechnology — 2.05%
Acorda Therapeutics, Inc. *	17,400	382,626
Alexion Pharmaceuticals, Inc. *	3,200	289,824
Alnylam Pharmaceuticals, Inc. *	14,000	143,360
Amylin Pharmaceuticals, Inc. *	8,100	214,731
Biogen Idec, Inc. *	14,200	1,856,650
Cubist Pharmaceuticals, Inc. *	8,200	328,984
Gilead Sciences, Inc. *	42,700	2,132,865
		5,349,040
Building products — 0.04%
A.O. Smith Corp.	2,200	101,552
Capital markets — 0.52%
Evercore Partners, Inc., Class A	3,200	79,072
Golub Capital BDC, Inc. 1	5,000	72,850
Invesco Ltd.	20,200	439,350
Morgan Stanley	50,400	673,344
PennantPark Investment Corp.	8,800	85,800
		1,350,416
Chemicals — 1.32%
Celanese Corp., Series A	10,800	429,948
Cytec Industries, Inc.	1,200	72,552

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (continued)
Chemicals — (concluded)
FMC Corp.	13,800	703,386
H.B. Fuller Co.	1,600	48,640
The Dow Chemical Co.	19,300	599,458
The Sherwin-Williams Co.	12,200	1,581,608
		3,435,592
Commercial banks — 0.83%
Banner Corp.	2,300	44,160
BBCN Bancorp, Inc. *	12,131	130,894
City National Corp.	1,300	64,584
East West Bancorp, Inc.	4,300	96,277
Prosperity Bancshares, Inc.	1,700	72,624
U.S. Bancorp	20,600	640,866
Wells Fargo & Co.	35,100	1,124,955
		2,174,360
Commercial services & supplies — 0.03%
Innerworkings, Inc. *,1	7,500	88,425
Communications equipment — 1.64%
Aruba Networks, Inc. *,1	3,000	39,420
Finisar Corp. *,1	3,700	53,095
Juniper Networks, Inc. *	23,900	411,080
NETGEAR, Inc. *	2,200	69,058
Nortel Networks Corp. *	25,433	331
QUALCOMM, Inc.	48,200	2,762,342
Riverbed Technology, Inc. *	56,900	933,160
		4,268,486
Computers & peripherals — 4.53%
Apple, Inc. *	16,300	9,416,999
NetApp, Inc. *	70,300	2,092,128
SanDisk Corp. *	8,800	287,760
		11,796,887
Construction & engineering — 0.02%
MasTec, Inc. *	2,500	40,875
Containers & packaging — 0.09%
Rock-Tenn Co., Class A	4,500	232,155
Diversified consumer services — 0.03%
Regis Corp.	4,600	84,226
Diversified financial services — 1.02%
Citigroup, Inc.	43,047	1,141,176
CME Group, Inc.	2,200	566,654

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (continued)
Diversified financial services — (concluded)
JPMorgan Chase & Co.	29,000	961,350
		2,669,180
Electric utilities — 0.55%
Edison International	17,200	773,312
NextEra Energy, Inc.	9,100	594,594
UNS Energy Corp.	2,000	74,980
		1,442,886
Electrical equipment — 0.52%
Regal-Beloit Corp.	1,800	108,522
Roper Industries, Inc.	12,300	1,245,006
		1,353,528
Electronic equipment, instruments & components — 0.04%
Audience, Inc. *	3,100	54,932
Rofin-Sinar Technologies, Inc. *	2,400	47,640
		102,572
Energy equipment & services — 2.51%
Baker Hughes, Inc.	28,200	1,176,786
C&J Energy Services, Inc. *,1	3,000	53,640
Ensco, PLC Class A	7,600	341,316
FMC Technologies, Inc. *	48,000	1,931,520
Halliburton Co.	10,700	321,642
McDermott International, Inc. *	57,800	586,670
Noble Corp. *	22,700	709,829
Schlumberger Ltd.	22,300	1,410,475
		6,531,878
Food & staples retailing — 1.08%
CVS Caremark Corp.	62,900	2,826,726
Food products — 0.56%
Bunge Ltd.	8,000	476,000
Kraft Foods, Inc., Class A	25,600	979,712
		1,455,712
Health care equipment & supplies — 0.56%
AtriCure, Inc. *	400	3,596
Baxter International, Inc.	8,700	440,394
CONMED Corp.	2,200	58,938
Greatbatch, Inc. *	5,400	112,104
Hill-Rom Holdings, Inc.	1,700	49,997
ICU Medical, Inc. *	1,200	61,740
Integra LifeSciences Holdings Corp. *	2,100	74,571

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (continued)
Health care equipment & supplies — (concluded)
Medtronic, Inc.	13,500	497,340
STERIS Corp.	2,500	74,650
The Cooper Cos., Inc.	1,100	93,698
		1,467,028
Health care providers & services — 1.48%
HCA Holdings, Inc.	20,100	522,399
McKesson Corp.	4,300	375,304
Patterson Cos., Inc.	1,700	56,508
PSS World Medical, Inc. *	4,800	97,104
UnitedHealth Group, Inc.	50,100	2,794,077
		3,845,392
Hotels, restaurants & leisure — 2.06%
Caribou Coffee Co., Inc. *	5,600	66,640
Chipotle Mexican Grill, Inc. *	2,500	1,032,675
Las Vegas Sands Corp.	36,300	1,676,334
McDonald’s Corp.	20,600	1,840,404
Starbucks Corp.	10,500	576,345
Vail Resorts, Inc.	2,400	104,328
WMS Industries, Inc. *	3,400	69,802
		5,366,528
Household products — 0.38%
Central Garden and Pet Co., Class A *	13,100	120,782
Colgate-Palmolive Co.	7,800	766,740
Spectrum Brands Holdings, Inc. *	2,600	89,752
		977,274
Industrial conglomerates — 0.73%
Danaher Corp.	36,700	1,907,299
Insurance — 0.35%
Lincoln National Corp.	20,700	427,869
MetLife, Inc.	13,700	400,177
Validus Holdings Ltd.	2,800	87,864
		915,910
Internet & catalog retail — 2.67%
Amazon.com, Inc. *	20,900	4,449,819
Priceline.com, Inc. *	4,000	2,501,960
		6,951,779
Internet software & services — 2.50%
Baidu, Inc., ADR *	16,000	1,884,320
Bazaarvoice, Inc. *	1,000	17,290

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (continued)
Internet software & services — (concluded)
Demandware, Inc. *,1	800	24,888
Digital River, Inc. *	1,900	27,740
ExactTarget, Inc. *	900	17,829
Facebook, Inc., Class A *,1	57,400	1,700,762
Google, Inc., Class A *	3,600	2,091,096
MercadoLibre, Inc.	9,600	674,304
ValueClick, Inc. *	4,100	71,914
		6,510,143
IT services — 2.92%
Fidelity National Information Services, Inc.	27,300	894,894
MasterCard, Inc., Class A	3,500	1,422,785
ServiceSource International, Inc. *,1	33,000	396,000
Teradata Corp. *	18,200	1,209,936
Visa, Inc., Class A	32,100	3,697,920
		7,621,535
Life sciences tools & services — 1.09%
Agilent Technologies, Inc.	54,300	2,207,838
Bio-Rad Laboratories, Inc., Class A *	4,500	448,245
Bruker Corp. *	11,800	174,994
		2,831,077
Machinery — 0.80%
CIRCOR International, Inc.	1,500	48,285
Cummins, Inc.	11,000	1,066,450
Greenbrier Cos., Inc. *	2,200	30,448
Illinois Tool Works, Inc.	15,000	842,250
Kaydon Corp.	1,900	42,389
Nordson Corp.	1,100	58,971
		2,088,793
Media — 1.86%
Cinemark Holdings, Inc.	5,400	124,524
Comcast Corp., Class A	74,100	2,142,231
Discovery Communications, Inc., Class A *	26,400	1,322,640
ReachLocal, Inc. *	3,700	37,333
Time Warner, Inc.	17,700	610,119
Valassis Communications, Inc. *,1	3,300	65,703
Viacom, Inc., Class B	11,500	548,895
		4,851,445
Metals & mining — 0.16%
Compass Minerals International, Inc.	1,100	78,276
Steel Dynamics, Inc.	30,900	325,686
		403,962

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (continued)
Multi-utilities — 0.21%
PG&E Corp.	12,800	559,360
Multiline retail — 1.56%
Dollar General Corp. *	49,600	2,425,936
Kohl’s Corp.	17,200	788,104
Macy’s, Inc.	22,600	859,930
		4,073,970
Oil, gas & consumable fuels — 2.41%
Alpha Natural Resources, Inc. *	6,200	64,976
Berry Petroleum Co., Class A	2,000	77,820
Cabot Oil & Gas Corp.	27,500	894,850
Concho Resources, Inc. *	18,500	1,623,190
EOG Resources, Inc.	15,700	1,559,010
EQT Corp.	13,900	644,682
Hess Corp.	14,700	642,390
Kodiak Oil & Gas Corp. *,1	9,800	79,478
Peabody Energy Corp.	12,100	282,656
Ultra Petroleum Corp. *,1	22,200	411,144
		6,280,196
Paper & forest products — 0.10%
International Paper Co.	8,600	251,120
Personal products — 0.91%
The Estee Lauder Cos., Inc., Class A	43,900	2,377,185
Pharmaceuticals — 1.85%
Allergan, Inc.	34,700	3,131,675
Hospira, Inc. *	12,600	393,876
Merck & Co., Inc.	18,209	684,294
Teva Pharmaceutical Industries Ltd., ADR	15,400	603,526
		4,813,371
Real estate investment trusts — 0.38%
American Capital Agency Corp.	16,600	542,322
Campus Crest Communities, Inc.	10,300	111,034
Hudson Pacific Properties, Inc.	4,900	78,498
LaSalle Hotel Properties	3,500	96,530
Mack-Cali Realty Corp.	2,800	76,272
Summit Hotel Properties, Inc.	10,200	81,294
		985,950
Road & rail — 1.26%
Hertz Global Holdings, Inc. *	85,100	1,158,211
Norfolk Southern Corp.	8,400	550,368

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (continued)
Road & rail — (concluded)
Union Pacific Corp.	14,200	1,581,880
		3,290,459
Semiconductors & semiconductor equipment — 1.09%
Atmel Corp. *	54,600	382,200
Broadcom Corp., Class A *	37,500	1,213,125
Intersil Corp., Class A	33,900	357,645
Micron Technology, Inc. *	44,900	262,216
ON Semiconductor Corp. *	3,400	22,916
Skyworks Solutions, Inc. *	22,600	607,036
		2,845,138
Software — 1.76%
Adobe Systems, Inc. *	37,000	1,148,850
Cadence Design Systems, Inc. *	6,200	63,240
Envivio, Inc. *,1	6,100	51,179
Guidewire Software, Inc. *,1	1,600	41,456
Infoblox, Inc. *	1,300	25,727
NICE Systems Ltd., ADR *	1,500	55,620
Proofpoint, Inc. *	1,800	25,686
RealPage, Inc. *,1	1,800	32,130
Salesforce.com, Inc. *	14,900	2,065,438
Solera Holdings, Inc.	1,100	48,840
Splunk, Inc. *	1,000	32,560
SS&C Technologies Holdings, Inc. *	4,100	96,678
Symantec Corp. *	54,200	804,328
Tangoe, Inc. *	2,900	55,999
Websense, Inc. *	1,800	33,444
		4,581,175
Specialty retail — 0.25%
The Home Depot, Inc.	13,000	641,420
Textiles, apparel & luxury goods — 2.74%
Coach, Inc.	15,200	1,025,240
Fifth & Pacific Cos., Inc. *	4,100	49,077
Lululemon Athletica, Inc. *,1	11,800	857,152
Movado Group, Inc.	3,600	99,720
Nike, Inc., Class B	23,400	2,531,412
Ralph Lauren Corp.	16,900	2,514,720
True Religion Apparel, Inc.	2,000	58,660
		7,135,981
Thrifts & mortgage finance — 0.05%
Brookline Bancorp, Inc.	8,900	78,231

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Security description	Shares	Value ($)
Common stocks — (concluded)
Thrifts & mortgage finance — (concluded)
EverBank Financial Corp. *	4,400	48,928
		127,159
Tobacco — 0.43%
Philip Morris International, Inc.	13,300	1,123,983
Trading companies & distributors — 0.06%
United Rentals, Inc. *,1	1,500	51,825
Watsco, Inc.	1,300	95,693
		147,518
Wireless telecommunication services — 0.92%
Crown Castle International Corp. *	28,500	1,556,100
MetroPCS Communications, Inc. *	69,700	446,080
NII Holdings, Inc. *	34,300	395,136
		2,397,316
Total common stocks (cost—$134,786,995)		139,141,175
Preferred stock — 0.00%
Consumer finance — 0.00%
Ally Financial, Inc.2 (cost—$98)	5	4,287
Investment company — 4.10%
UBS Credit Bond Relationship Fund*,3 (cost—$9,046,919)	671,919	10,696,010
	Number of
	warrants
Warrants — 0.00%
Commercial banks — 0.00%
CMP Susquehanna Radio Holdings Corp., expires 03/23/19*,4,5 (cost—$27)	2,665	27
	Face
	amount ($)
US government obligations — 8.48%
US Treasury Bonds
3.125%, due 11/15/41	470,000	513,916
3.125%, due 02/15/42	1,255,000	1,372,265
US Treasury Notes
0.125%, due 04/15/17	1,287,380	1,364,019
0.250%, due 04/30/14	11,885,000	11,881,755
0.250%, due 05/15/15	80,000	79,763
0.625%, due 05/31/17	250,000	249,453

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
US government obligations — (concluded)
0.875%, due 01/31/17	515,000	520,914
0.875%, due 04/30/17	1,975,000	1,995,984
1.000%, due 03/31/17	345,000	350,822
1.750%, due 05/15/22	1,235,000	1,254,297
1.875%, due 06/30/15	160,000	167,237
2.000%, due 02/15/22	2,265,000	2,356,486
Total US government obligations (cost—$21,839,379)		22,106,911
Mortgage & agency debt securities — 6.54%
Federal Home Loan Mortgage Corporation Certificates,**
0.500%, due 04/17/15	980,000	979,430
1.000%, due 06/29/17	600,000	599,687
4.000%, due 01/01/41	617,383	656,072
5.000%, due 03/01/38	230,158	248,160
5.000%, due 11/01/38	23,204	24,994
5.000%, due 12/01/38	149,720	161,268
5.500%, due 05/01/37	1,070,498	1,185,633
5.500%, due 08/01/40	86,190	94,329
6.000%, due 10/01/36	167,054	185,804
6.500%, due 08/01/28	250,034	286,933
2.500%, TBA	900,000	925,734
4.500%, TBA	100,000	106,781
Federal National Mortgage Association Certificates,**
4.000%, due 12/01/39	714,412	761,361
4.000%, due 01/01/41	477,996	509,305
4.000%, due 02/01/41	184,672	196,825
4.000%, due 09/01/41	434,414	463,004
4.500%, due 09/01/37	1,286,028	1,383,779
4.500%, due 02/01/39	159,049	170,691
4.500%, due 07/01/41	414,367	446,640
4.500%, due 09/01/41	406,182	437,818
5.000%, due 09/01/39	547,523	600,690
5.000%, due 10/01/39	77,985	84,608
5.000%, due 05/01/40	97,568	106,219
5.000%, due 09/01/41	423,977	461,967
5.500%, due 08/01/39	338,028	370,503
6.000%, due 06/01/33	6,982	7,874
6.000%, due 08/01/37	206,186	230,475
7.000%, due 08/01/32	489,522	580,289
7.500%, due 02/01/33	8,518	10,331
3.000%, TBA	250,000	256,211
4.500%, TBA	100,000	107,266
5.000%, TBA	325,000	351,762
5.500%, TBA	200,000	217,875

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Mortgage & agency debt securities — (concluded)
Government National Mortgage Association Certificates,
6.500% , due 10/15/28	4,520	5,292
Government National Mortgage Association Certificates I,
3.500%, TBA	675,000	720,352
4.000%, TBA	225,000	245,586
Government National Mortgage Association Certificates II,
3.000%, TBA	500,000	517,109
3.500%, due 12/20/26	626,159	670,638
4.000%, due 07/20/26	367,037	392,547
4.500%, due 05/20/40	348,663	385,100
6.000%, due 11/20/28	2,253	2,544
6.000%, due 02/20/29	5,250	5,933
6.000%, due 02/20/34	778,316	876,577
Total mortgage & agency debt securities (cost—$16,477,682)		17,031,996
Collateralized mortgage obligations — 0.48%
Arkle Master Issuer PLC, Series 2012-1A, Class 2A1,
2.166%, due 05/17/606,7	255,000	257,955
First Horizon Mortgage Pass-Through Trust, Series 2004-FL1, Class 1A1,
0.509%, due 02/25/357	146,186	125,883
Fosse Master Issuer PLC, Series 2012-1A, Class 2A2,
1.727%, due 10/18/546,7	225,000	224,964
Holmes Master Issuer PLC,
Series 2010-1A, Class A2,
1.867%, due 10/15/546,7	120,000	120,635
Series 2012-1A, Class A2,
2.117%, due 10/15/546,7	375,000	378,622
Silverstone Master Issuer, Series 2012-1A, Class 1A,
2.016%, due 01/21/556,7	150,000	151,283
Total collateralized mortgage obligations (cost—$1,276,637)		1,259,342
Commercial mortgage-backed securities — 0.88%
Banc of America Commercial Mortgage, Inc., Series 2007-4, Class AM
5.983%, due 02/10/517	250,000	240,091
Bear Stearns Commercial Mortgage Securities, Series 2006-PW12, Class A4,
5.901%, due 09/11/387	300,000	339,900
FDIC Structured Sale Guaranteed Notes, Series 2010-C1, Class A,
2.980%, due 12/06/206	270,563	279,256
Fosse Master Issuer PLC, Series 2011-1A, Class A2
1.866%, due 10/18/546,7	250,000	251,702
Greenwich Capital Commercial Funding Corp., Series 2007-GG9, Class AM,
5.475%, due 03/10/39	250,000	239,096
JP Morgan Chase Commercial Mortgage Securities Corp.,
Series 2006-CB17, Class AM
5.464%, due 12/12/43	275,000	257,785
Series 2007-LD11, Class A4,
6.009%, due 06/15/497	200,000	215,950
Morgan Stanley Dean Witter Capital I, Series 2002-IQ3, Class B
5.240%, due 09/15/37	100,000	101,218
Morgan Stanley Re-REMIC Trust, Series 2009-GG10, Class A4B,
5.979%, due 08/12/456,7	360,000	361,529
Total commercial mortgage-backed securities (cost—$2,244,321)		2,286,527

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — 8.42%
Aerospace & defense — 0.01%
BE Aerospace, Inc.
6.875%, due 10/01/20	30,000	32,925
Airlines — 0.06%
AMGH Merger Sub, Inc.
9.250%, due 11/01/186	25,000	25,313
Delta Air Lines 2007-1, Class A Pass-Through Trust
6.821%, due 08/10/22	84,287	91,452
Delta Air Lines, Inc.
12.250%, due 03/15/156,8	30,000	32,400
		149,165
Automobile OEM — 0.11%
Chrysler Group LLC/CG Co-Issuer, Inc.
8.000%, due 06/15/191	80,000	80,200
Ford Motor Co.
7.450%, due 07/16/311	160,000	208,400
		288,600
Automotive parts — 0.10%
Daimler Finance North America LLC
8.500%, due 01/18/31	65,000	99,211
Meritor, Inc.
10.625%, due 03/15/18	30,000	32,475
Navistar International Corp.
8.250%, due 11/01/21	30,000	31,500
Tenneco, Inc.
7.750%, due 08/15/18	100,000	107,500
		270,686
Banking-non-US — 0.12%
Eksportfinans ASA
3.000%, due 11/17/14	45,000	42,754
HSBC Holdings PLC
4.000%, due 03/30/22	250,000	254,466
NB Capital Trust II
7.830%, due 12/15/26	25,000	25,000
		322,220
Banking-US — 0.70%
Bank of America Corp.
3.875%, due 03/22/17	125,000	124,588
5.650%, due 05/01/18	70,000	72,915
BankAmerica Capital II
8.000%, due 12/15/26	25,000	25,063
Capital One Financial Corp.
2.150%, due 03/23/15	75,000	75,322
CIT Group, Inc.
4.750%, due 02/15/156	435,000	432,825
5.500%, due 02/15/196	80,000	77,800

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Banking-US — (concluded)
Citigroup Capital XXI
8.300%, due 12/21/577	50,000	50,550
Citigroup, Inc.
6.125%, due 05/15/18	150,000	163,237
JPMorgan Chase & Co.
5.400%, due 01/06/42	125,000	135,382
Regions Financial Corp.
5.750%, due 06/15/15	50,000	52,500
The Goldman Sachs Group, Inc.
3.300%, due 05/03/15	55,000	54,202
5.750%, due 01/24/22	160,000	164,152
Washington Mutual, Inc.
5.500%, due 01/15/135,9	585,000	59
Wells Fargo Bank N.A.
5.950%, due 08/26/36	310,000	355,022
Zions Bancorp.
5.500%, due 11/16/15	30,000	31,141
		1,814,758
Beverage/bottling — 0.04%
Constellation Brands, Inc.
7.250%, due 05/15/17	40,000	45,300
8.375%, due 12/15/14	60,000	68,025
		113,325
Building materials — 0.04%
Hanson Ltd.
6.125%, due 08/15/16	40,000	42,300
Vulcan Materials Co.
7.500%, due 06/15/21	50,000	54,000
		96,300
Business services/office equipment — 0.04%
West Corp.
7.875%, due 01/15/19	45,000	45,113
11.000%, due 10/15/161	50,000	52,687
		97,800
Cable — 0.08%
Comcast Corp.
6.300%, due 11/15/17	100,000	120,529
6.950%, due 08/15/37	60,000	77,195
		197,724
Chemicals — 0.16%
Ashland, Inc.
9.125%, due 06/01/17	40,000	43,900
Celanese US Holdings LLC
5.875%, due 06/15/21	50,000	52,125

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Chemicals — (concluded)
6.625%, due 10/15/18	25,000	26,437
CF Industries, Inc.
7.125%, due 05/01/20	145,000	175,450
Georgia Gulf Corp.
9.000%, due 01/15/171,6	40,000	44,900
Hexion US Finance Corp./Hexion Nova Scotia Finance ULC
8.875%, due 02/01/18	50,000	49,750
Ineos Group Holdings PLC
8.500%, due 02/15/161,6	15,000	13,538
Momentive Performance Materials, Inc.
9.000%, due 01/15/21	25,000	18,875
		424,975
Coal — 0.01%
Arch Coal, Inc.
8.750%, due 08/01/161	25,000	24,000
Commercial services — 0.01%
DynCorp International, Inc.
10.375%, due 07/01/17	20,000	17,150
Interactive Data Corp.
10.250%, due 08/01/18	5,000	5,538
		22,688
Consumer products — 0.05%
Mead Products LLC/ACCO Brands Corp.
6.750%, due 04/30/206	25,000	25,688
Reynolds Group Issuer, Inc./Reynolds Group Issuer LLC/Reynolds Group Issuer Lu
7.750%, due 10/15/166,8	100,000	105,500
		131,188
Consumer products-non durables — 0.05%
Toys R US Property Co. II LLC
8.500%, due 12/01/17	45,000	46,294
Tupperware Brands Corp.
4.750%, due 06/01/21	90,000	93,605
		139,899
Consumer services — 0.02%
Avis Budget Car Rental/Avis Budget Finance, Inc.
9.625%, due 03/15/18	20,000	21,725
Dell, Inc.
5.400%, due 09/10/40	35,000	37,564
		59,289

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Distribution/wholesale — 0.02%
McJunkin Red Man Corp.
9.500%, due 12/15/16	60,000	64,200
Diversified financial services — 0.01%
Capital One Capital III
7.686%, due 08/15/36	35,000	35,350
Diversified manufacturing — 0.10%
Bombardier, Inc.
7.500%, due 03/15/186	20,000	21,800
7.750%, due 03/15/206	125,000	137,187
Coleman Cable, Inc.
9.000%, due 02/15/18	20,000	20,750
SPX Corp.
7.625%, due 12/15/14	65,000	71,663
The Goodyear Tire & Rubber Co.
7.000%, due 05/15/221	20,000	19,600
		271,000
Electric-generation — 0.16%
Calpine Construction Finance/CCFC Finance Corp.
8.000%, due 06/01/166	50,000	53,625
Calpine Corp.
7.875%, due 07/31/206	125,000	132,500
GenOn Energy, Inc.
9.500%, due 10/15/18	100,000	93,000
NRG Energy, Inc.
7.625%, due 05/15/19	50,000	48,875
8.500%, due 06/15/191	15,000	15,000
The AES Corp.
8.000%, due 06/01/20	55,000	61,875
		404,875
Electric-integrated — 0.23%
Appalachian Power Co.
4.600%, due 03/30/21	130,000	145,687
DPL, Inc.
7.250%, due 10/15/216	60,000	65,250
E.ON International Finance BV
5.800%, due 04/30/186	80,000	95,650
MidAmerican Energy Holdings Co.
5.950%, due 05/15/37	100,000	125,681
Oncor Electric Delivery Co. LLC
6.800%, due 09/01/18	80,000	95,318
Southern California Edison Co.
4.050%, due 03/15/42	75,000	78,090
		605,676

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Electronics — 0.07%
Freescale Semiconductor, Inc.
9.250%, due 04/15/186	25,000	26,312
10.750%, due 08/01/201	60,000	64,200
KEMET Corp.
10.500%, due 05/01/18	25,000	26,063
Sanmina-SCI Corp.
7.000%, due 05/15/191,6	45,000	43,537
8.125%, due 03/01/161	12,000	12,345
		172,457
Energy-exploration & production — 0.41%
Alta Mesa Holdings/Alta Mesa Finance Services Corp.
9.625%, due 10/15/18	100,000	98,500
Apache Corp.
5.250%, due 02/01/42	90,000	104,800
ATP Oil & Gas Corp.
11.875%, due 05/01/151	25,000	13,313
Berry Petroleum Co.
6.750%, due 11/01/20	50,000	51,750
Connacher Oil and Gas Ltd.
8.500%, due 08/01/191,6	50,000	46,500
Denbury Resources, Inc.
8.250%, due 02/15/20	25,000	27,000
9.750%, due 03/01/16	75,000	81,562
Forest Oil Corp.
7.250%, due 06/15/191	75,000	68,250
8.500%, due 02/15/14	30,000	31,500
Helix Energy Solutions
9.500%, due 01/15/166	58,000	60,755
Hilcorp Energy I LP/Hilcorp Finance Co.
7.625%, due 04/15/216	25,000	26,125
8.000%, due 02/15/206	20,000	21,300
Linn Energy LLC/Linn Energy Finance Corp.
7.750%, due 02/01/21	50,000	51,125
8.625%, due 04/15/20	75,000	79,500
Quicksilver Resources, Inc.
7.125%, due 04/01/16	50,000	43,750
11.750%, due 01/01/16	30,000	30,750
Range Resources Corp.
5.750%, due 06/01/21	25,000	25,750
7.250%, due 05/01/18	25,000	26,375
Samson Investment Co.
9.750%, due 02/15/206	70,000	69,650
SandRidge Energy, Inc.
8.750%, due 01/15/20	45,000	46,125
9.875%, due 05/15/16	45,000	49,050
Swift Energy Co.
7.875%, due 03/01/22	25,000	25,250
		1,078,680

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Energy-independent — 0.18%
Anadarko Petroleum Corp.
5.950%, due 09/15/16	110,000	124,727
6.450%, due 09/15/36	85,000	99,327
Chesapeake Energy Corp.
9.500%, due 02/15/151	115,000	121,325
Comstock Resources, Inc.
8.375%, due 10/15/17	5,000	4,888
Encore Acquisition Co.
9.500%, due 05/01/16	30,000	32,700
Key Energy Services, Inc.
6.750%, due 03/01/21	75,000	75,281
		458,248
Energy-integrated — 0.03%
ConocoPhillips
6.500%, due 02/01/39	55,000	75,532
Energy-oilfield services — 0.06%
Cie Generale de Geophysique-Veritas
7.750%, due 05/15/17	35,000	36,050
Transocean, Inc.
6.800%, due 03/15/38	100,000	115,999
		152,049
Energy-refining & marketing — 0.07%
Tesoro Corp.
9.750%, due 06/01/191	55,000	61,875
Valero Energy Corp.
6.625%, due 06/15/37	110,000	122,262
		184,137
Entertainment — 0.13%
WMG Acquisition Corp.
9.500%, due 06/15/16	325,000	346,937
Environmental — 0.04%
Casella Waste Systems, Inc.
11.000%, due 07/15/14	25,000	26,313
Republic Services, Inc.
3.550%, due 06/01/22	80,000	81,075
		107,388
Finance-captive automotive — 0.01%
AmeriGas Finance LLC/AmeriGas Finance Corp.
6.750%, due 05/20/20	35,000	34,475

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Finance-diversified — 0.21%
Merrill Lynch & Co., Inc.
5.000%, due 01/15/15	175,000	179,724
Wells Fargo & Co. MTN
2.100%, due 05/08/17	255,000	252,401
4.600%, due 04/01/21	115,000	126,542
		558,667
Finance-noncaptive diversified — 0.13%
Ally Financial, Inc.
6.750%, due 12/01/14	100,000	104,000
8.000%, due 03/15/20	75,000	84,562
8.300%, due 02/12/15	65,000	69,550
E*Trade Financial Corp.
12.500%, due 11/30/17	63,000	72,293
		330,405
Finance-other — 0.40%
Caterpillar Financial Services Corp.
2.850%, due 06/01/22	130,000	131,697
Ford Motor Credit Co. LLC
6.625%, due 08/15/17	100,000	116,114
8.125%, due 01/15/20	110,000	139,705
12.000%, due 05/15/15	135,000	170,437
FTI Consulting, Inc.
6.750%, due 10/01/20	25,000	26,312
General Electric Capital Corp. MTN
4.650%, due 10/17/21	125,000	137,334
Icahn Enterprises LP/Icahn Enterprises Finance Corp.
8.000%, due 01/15/18	25,000	26,469
International Lease Finance Corp.
7.125%, due 09/01/186	100,000	110,000
8.625%, due 09/15/158	105,000	114,450
SquareTwo Financial Corp.
11.625%, due 04/01/17	75,000	69,375
		1,041,893
Food — 0.11%
Kraft Foods, Inc.
6.500%, due 02/09/40	100,000	127,390
Michael Foods, Inc.
9.750%, due 07/15/18	50,000	54,125
Smithfield Foods, Inc.
10.000%, due 07/15/14	22,000	25,300
Tyson Foods, Inc.
10.500%, due 03/01/14	35,000	40,075
Viskase Cos., Inc.
9.875%, due 01/15/186	40,000	41,500
		288,390

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Food-wholesale — 0.04%
ARAMARK Corp.
8.500%, due 02/01/15	85,000	87,020
US Foodservice
8.500%, due 06/30/191,6	25,000	25,187
		112,207
Food/beverage — 0.04%
Anheuser-Busch InBev Worldwide, Inc.
8.200%, due 01/15/39	60,000	98,274
Gaming — 0.24%
Boyd Gaming Corp.
9.125%, due 12/01/181	35,000	35,875
Caesars Entertainment Operating Co., Inc.
5.625%, due 06/01/151	75,000	61,875
10.000%, due 12/15/15	85,000	74,375
11.250%, due 06/01/17	55,000	58,437
CityCenter Holdings LLC/CityCenter Finance Corp.
10.750%, due 01/15/171,10	50,000	51,328
Marina District Finance Co., Inc.
9.500%, due 10/15/151	45,000	42,638
MGM Resorts International
10.000%, due 11/01/161	85,000	93,075
11.125%, due 11/15/17	35,000	39,200
Shingle Springs Tribal Gaming Authority
9.375%, due 06/15/156	75,000	56,062
Tunica-Biloxi Gaming Authority
9.000%, due 11/15/156	40,000	38,000
Yonkers Racing Corp.
11.375%, due 07/15/166	80,000	85,000
		635,865
Gas distributors — 0.03%
Ferrellgas Partners LP
8.625%, due 06/15/20	26,000	23,400
9.125%, due 10/01/17	20,000	20,700
Niska Gas Storage US LLC/Niska Gas Storage Canada ULC
8.875%, due 03/15/18	45,000	42,863
		86,963
Gas pipelines — 0.32%
Atlas Pipeline Partners LP/Atlas Pipeline Finance Corp.
8.750%, due 06/15/18	25,000	26,500
Crosstex Energy LP/Crosstex Energy Finance Corp.
8.875%, due 02/15/18	80,000	84,000
Energy Transfer Partners LP
5.200%, due 02/01/22	125,000	132,138
7.500%, due 07/01/38	75,000	85,214

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Gas pipelines — (concluded)
Kinder Morgan Energy Partners LP
3.950%, due 09/01/22	85,000	85,840
6.500%, due 09/01/39	150,000	172,038
Sonat, Inc.
7.000%, due 02/01/18	150,000	161,020
Trans-Canada Pipelines Ltd.
7.625%, due 01/15/39	50,000	73,919
		820,669
Health care — 0.24%
Capella Healthcare, Inc.
9.250%, due 07/01/17	10,000	10,000
Carriage Services, Inc.
7.875%, due 01/15/15	20,000	20,150
CHS/Community Health Systems, Inc.
8.000%, due 11/15/19	25,000	25,531
8.875%, due 07/15/151	16,000	16,410
CVS Caremark Corp.
6.125%, due 09/15/39	60,000	73,950
ExamWorks Group, Inc.
9.000%, due 07/15/196	70,000	71,050
Fresenius Medical Care US Finance II, Inc.
5.625%, due 07/31/196	50,000	49,625
HCA, Inc.
5.875%, due 03/15/22	25,000	24,813
7.500%, due 02/15/22	100,000	104,812
8.500%, due 04/15/19	25,000	27,594
Multiplan, Inc.
9.875%, due 09/01/186	125,000	132,500
Tenet Healthcare Corp.
6.875%, due 11/15/31	50,000	41,937
United Surgical Partners International, Inc.
9.000%, due 04/01/206	25,000	25,938
US Oncology, Inc., Escrow
(related to 9.125% bonds, due 08/15/17)11	30,000	450
		624,760
Home construction — 0.02%
Standard Pacific Corp.
10.750%, due 09/15/16	25,000	29,188
Toll Brothers Finance Corp.
8.910%, due 10/15/17	10,000	12,212
		41,400
Housewares — 0.00%
Libbey Glass, Inc.
10.000%, due 02/15/15	3,000	3,195

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Industrial-other — 0.08%
Belden, Inc.
9.250%, due 06/15/19	50,000	54,875
Iron Mountain, Inc.
8.000%, due 06/15/20	115,000	120,750
RBS Global, Inc./Rexnord LLC
8.500%, due 05/01/18	30,000	31,875
		207,500
Insurance-life — 0.13%
American International Group, Inc.
3.000%, due 03/20/15	180,000	181,773
Hartford Financial Services Group, Inc.
6.625%, due 04/15/42	40,000	41,585
MetLife, Inc.
6.400%, due 12/15/36	130,000	123,513
		346,871
Insurance-multiline — 0.06%
Glen Meadow Pass-Through Trust
6.505%, due 02/12/676,7	60,000	44,250
Prudential Financial, Inc. MTN
6.625%, due 12/01/37	100,000	116,589
		160,839
Insurance-personal & casualty — 0.08%
Berkshire Hathaway Finance Corp.
3.000%, due 05/15/221	40,000	40,068
Liberty Mutual Group, Inc.
7.800%, due 03/15/376	25,000	24,375
10.750%, due 06/15/586,7	70,000	96,600
XL Group PLC, Series E
6.500%, due 04/15/177,12	50,000	38,500
		199,543
Internet software & services — 0.03%
Equinix, Inc.
8.125%, due 03/01/18	75,000	81,938
Investments & miscellaneous financial services — 0.03%
Tomkins LLC/Tomkins, Inc.
9.000%, due 10/01/188	63,000	69,221
Leisure — 0.03%
Brunswick Corp.
11.250%, due 11/01/166	25,000	29,188

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Leisure — (concluded)
Royal Caribbean Cruises Ltd.
7.500%, due 10/15/27	40,000	40,200
		69,388
Lodging — 0.07%
Diamond Resorts Corp.
12.000%, due 08/15/18	110,000	118,525
Felcor Lodging LP
6.750%, due 06/01/19	25,000	25,062
Host Hotels & Resorts LP
9.000%, due 05/15/171	40,000	44,300
		187,887
Machinery-agriculture & construction — 0.08%
Case New Holland, Inc.
7.875%, due 12/01/17	105,000	119,700
The Manitowoc Co., Inc.
8.500%, due 11/01/20	75,000	80,437
		200,137
Media-broadcast/outdoor — 0.06%
Clear Channel Communications, Inc.
10.750%, due 08/01/16	85,000	55,250
News America, Inc.
6.200%, due 12/15/34	45,000	50,308
Nexstar Broadcasting, Inc./Mission Broadcasting, Inc.
8.875%, due 04/15/17	25,000	26,125
XM Satellite Radio, Inc.
13.000%, due 08/01/136	25,000	28,062
		159,745
Media-cable — 0.27%
Cablevision Systems Corp.
8.625%, due 09/15/17	65,000	71,013
CSC Holdings LLC
8.625%, due 02/15/19	25,000	27,875
DIRECTV Holdings LLC/DIRECTV Financing Co., Inc.
6.000%, due 08/15/40	100,000	109,600
DISH DBS Corp.
7.750%, due 05/31/15	50,000	54,375
7.875%, due 09/01/19	120,000	133,500
Time Warner Cable, Inc.
6.550%, due 05/01/37	40,000	46,824
6.750%, due 07/01/18	165,000	199,926
Time Warner, Inc.
6.100%, due 07/15/40	45,000	51,627
		694,740

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Media-diversified — 0.02%
Entravision Communications Corp.
8.750%, due 08/01/17	47,000	49,115
Media-non cable — 0.06%
Gannett Co., Inc.
8.750%, due 11/15/14	25,000	28,250
Intelsat Jackson Holdings SA
7.250%, due 10/15/20	75,000	74,625
LIN Television Corp.
8.375%, due 04/15/18	25,000	25,625
Nielsen Finance LLC/Nielsen Finance Co.
11.625%, due 02/01/14	13,000	14,771
Sinclair Television Group
9.250%, due 11/01/176	20,000	22,000
		165,271
Media-publishing — 0.03%
Cengage Learning Acquisitions, Inc.
10.500%, due 01/15/156	40,000	29,800
The McClatchy Co.
11.500%, due 02/15/17	35,000	35,350
		65,150
Media-services — 0.01%
Nielsen Finance LLC/Nielson Finance Co.
7.750%, due 10/15/18	25,000	26,875
Metals & mining — 0.27%
AngloGold Ashanti Holdings PLC
5.375%, due 04/15/20	75,000	77,050
CONSOL Energy, Inc.
8.000%, due 04/01/17	45,000	45,112
Mirabela Nickel Ltd.
8.750%, due 04/15/186	30,000	21,600
Murray Energy Corp.
10.250%, due 10/15/156	125,000	111,250
Novelis, Inc.
8.375%, due 12/15/17	50,000	52,750
Peabody Energy Corp.
7.375%, due 11/01/16	50,000	55,375
Ryerson, Inc.
12.000%, due 11/01/158	105,000	107,100
Teck Resources Ltd.
6.250%, due 07/15/41	50,000	55,589
Vale Overseas Ltd.
4.375%, due 01/11/22	125,000	124,947

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Metals & mining — (concluded)
6.875%, due 11/21/36	35,000	40,050
		690,823
Metals/mining excluding steel — 0.06%
FMG Resources (August 2006) Pty Ltd.
7.000%, due 11/01/156	75,000	75,000
Inmet Mining Corp.
8.750%, due 06/01/206	70,000	68,250
Penn Virginia Resource Partners LP/Penn Virginia Resource Finance Corp. II
8.375%, due 06/01/206	25,000	25,000
		168,250
Oil & gas — 0.02%
BreitBurn Energy Partners LP/BreitBurn Finance Corp.
7.875%, due 04/15/226	50,000	49,000
Oil field equipment & services — 0.04%
SESI LLC
7.125%, due 12/15/216	85,000	92,650
Oil refining & marketing — 0.03%
Phillips 66
4.300%, due 04/01/226	75,000	78,107
Packaging & containers — 0.09%
Berry Plastics Corp.
8.250%, due 11/15/15	30,000	31,725
Graphic Packaging International, Inc.
9.500%, due 06/15/17	5,000	5,525
Owens-Brockway Glass Container, Inc.
7.375%, due 05/15/16	100,000	110,500
Sealed Air Corp.
8.375%, due 09/15/216	40,000	44,000
Solo Cup Co.
8.500%, due 02/15/14	35,000	35,000
		226,750
Paper & forest products — 0.04%
Boise Paper Holdings LLC/Boise Finance Co.
9.000%, due 11/01/17	15,000	16,538
Georgia-Pacific LLC
8.875%, due 05/15/31	35,000	49,224
Mercer International, Inc.
9.500%, due 12/01/17	35,000	36,312
		102,074

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Pharmaceuticals — 0.15%
Mylan, Inc.
7.625%, due 07/15/176	50,000	54,563
Teva Pharmaceutical Finance Co. BV
2.400%, due 11/10/16	125,000	130,077
Teva Pharmaceutical Finance IV BV
3.650%, due 11/10/21	90,000	94,320
Valeant Pharmaceuticals International
7.000%, due 10/01/206	75,000	72,562
Warner Chilcott Co. LLC/ Warner Chilcott Finance LLC
7.750%, due 09/15/18	30,000	31,650
		383,172
Railroads — 0.04%
Burlington Northern Santa Fe LLC
6.150%, due 05/01/37	40,000	50,405
Norfolk Southern Corp.
3.250%, due 12/01/21	50,000	52,236
		102,641
Real estate investment trusts — 0.14%
CB Richard Ellis Services, Inc.
11.625%, due 06/15/17	50,000	56,500
Developers Diversified Realty Corp.
9.625%, due 03/15/16	70,000	85,236
DuPont Fabros Technology LP
8.500%, due 12/15/17	75,000	81,750
ERP Operating LP
4.750%, due 07/15/20	35,000	38,665
5.375%, due 08/01/16	100,000	111,906
		374,057
Retail-department — 0.04%
JC Penney Corp., Inc.
7.125%, due 11/15/23	60,000	57,000
Macy’s Retail Holdings, Inc.
6.375%, due 03/15/37	35,000	41,976
		98,976
Retail-discount — 0.01%
Target Corp.
7.000%, due 01/15/38	25,000	35,831

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Retail-specialty — 0.22%
Burlington Coat Factory Warehouse Corp.
10.000%, due 02/15/19	30,000	30,975
Ingles Markets, Inc.
8.875%, due 05/15/17	70,000	75,775
Limited Brands, Inc.
8.500%, due 06/15/19	45,000	52,931
Michaels Stores, Inc.
7.750%, due 11/01/18	25,000	26,063
11.375%, due 11/01/161	50,000	53,126
Petco Animal Supplies, Inc.
9.250%, due 12/01/181,6	60,000	64,500
QVC, Inc.
7.125%, due 04/15/176	20,000	21,200
7.500%, due 10/01/196	75,000	81,562
Rite Aid Corp.
10.375%, due 07/15/161	60,000	63,225
SUPERVALU, Inc.
8.000%, due 05/01/161	35,000	34,913
YCC Holdings LLC/Yankee Finance, Inc.
10.250%, due 02/15/1610	75,000	75,187
		579,457
Software/services — 0.02%
MedAssets, Inc.
8.000%, due 11/15/18	50,000	51,625
Steel producers/products — 0.06%
AK Steel Corp.
7.625%, due 05/15/20	50,000	46,250
Severstal Columbus LLC
10.250%, due 02/15/18	50,000	52,000
US Steel Corp.
7.375%, due 04/01/201	50,000	48,750
		147,000
Support-services — 0.03%
Iron Mountain, Inc.
8.375%, due 08/15/21	70,000	74,725
Supranational — 0.08%
European Investment Bank
2.875%, due 01/15/15	195,000	204,506
Technology-hardware — 0.05%
CDW LLC/CDW Finance Corp.
12.535%, due 10/12/17	50,000	53,500

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Technology-hardware — (concluded)
Jabil Circuit, Inc.
8.250%, due 03/15/18	25,000	29,000
Seagate HDD Cayman
7.750%, due 12/15/18	50,000	53,875
		136,375
Technology-software — 0.05%
Epicor Software Corp.
8.625%, due 05/01/19	15,000	15,038
First Data Corp.
9.875%, due 09/24/151	75,000	74,437
11.250%, due 03/31/161	25,000	21,750
Unisys Corp.
12.750%, due 10/15/146	25,000	27,500
		138,725
Telecom-satellite — 0.04%
Intelsat Bermuda Ltd.
11.250%, due 02/04/17	110,000	108,075
Telecom-wireless — 0.28%
America Movil SAB de CV
5.000%, due 03/30/20	135,000	150,895
Cellco Partnership/Verizon Wireless Capital LLC
8.500%, due 11/15/18	90,000	123,113
Clearwire Communications LLC/Clearwire Finance, Inc.
12.000%, due 12/01/156	25,000	21,813
Cricket Communications, Inc.
7.750%, due 05/15/16	50,000	52,750
10.000%, due 07/15/151	50,000	51,125
Nextel Communications, Inc.
7.375%, due 08/01/15	150,000	146,625
SBA Telecommunications, Inc.
8.250%, due 08/15/19	49,000	53,165
Vimpel Communications Via VIP Finance Ireland Ltd. OJSC
9.125%, due 04/30/186	100,000	103,500
Wind Acquisition Finance SA
11.750%, due 07/15/176	40,000	34,000
		736,986
Telephone-integrated — 0.48%
AT&T, Inc.
1.600%, due 02/15/17	150,000	150,541
6.500%, due 09/01/37	80,000	100,771
CenturyLink, Inc.
6.450%, due 06/15/21	100,000	103,592
Embarq Corp.
7.995%, due 06/01/36	50,000	51,231

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)	Value ($)
Corporate bonds — (continued)
Telephone-integrated — (concluded)
Frontier Communications Corp.
7.875%, due 04/15/151	30,000	32,325
8.250%, due 04/15/171	115,000	118,737
Level 3 Communications, Inc.
11.875%, due 02/01/19	25,000	26,813
Level 3 Financing, Inc.
8.625%, due 07/15/206	25,000	25,500
10.000%, due 02/01/18	50,000	53,875
PAETEC Holding Corp.
9.875%, due 12/01/18	65,000	71,337
Sprint Nextel Corp.
6.000%, due 12/01/16	50,000	45,750
8.375%, due 08/15/17	75,000	72,000
9.000%, due 11/15/186	25,000	27,063
9.125%, due 03/01/176	25,000	24,812
Verizon Communications, Inc.
6.100%, due 04/15/18	210,000	255,185
Videotron Ltee
5.000%, due 07/15/226	35,000	34,125
Virgin Media Secured Finance PLC
6.500%, due 01/15/18	50,000	54,500
		1,248,157
Textile/apparel — 0.01%
Quiksilver, Inc.
6.875%, due 04/15/151	25,000	24,625
Theaters & entertainment — 0.03%
AMC Entertainment, Inc.
9.750%, due 12/01/20	50,000	53,750
Production Resource Group, Inc.
8.875%, due 05/01/19	15,000	11,663
		65,413
Tobacco — 0.14%
Altria Group, Inc.
9.950%, due 11/10/38	65,000	103,796
Philip Morris International, Inc.
2.900%, due 11/15/21	150,000	154,635
Reynolds American, Inc.
7.625%, due 06/01/16	80,000	96,589
		355,020
Transportation services — 0.06%
Marquette Transportation Co./Marquette Transportation Finance Corp.
10.875%, due 01/15/17	50,000	52,250
Navios Maritime Acquisition Corp./Navios Acquisition Finance US, Inc.
8.625%, due 11/01/17	75,000	70,500

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

	Face
Security description	amount ($)		Value ($)
Corporate bonds — (concluded)
Transportation services — (concluded)
Navios Maritime Holdings, Inc./Navios Maritime Finance US, Inc.
8.875%, due 11/01/17	30,000		30,750
			153,500
Total corporate bonds (cost—$21,879,012)			21,929,974
Non-US government obligations — 0.07%
Colombia Government International Bond
4.375%, due 07/12/21	100,000		109,000
Mexico Government International Bond MTN
4.750%, due 03/08/44	75,000		76,125
Total non-US government obligations (cost—$173,551)			185,125
Repurchase agreement — 18.72%
Repurchase agreement dated 05/31/12 with State Street Bank & Trust Co., 0.010% due 06/01/12, collateralized by $21,712,167 Federal Home Loan Bank obligations, 0.875% to 1.375% due 12/27/13 to 05/28/14, $11,040,637 Federal Home Loan Mortgage Corp. obligations, 0.540% to 0.750% due 09/22/14 to 11/15/14, $7,378,880 Federal National Mortgage Association obligations, 0.810% to 2.625% due 11/20/14 to 11/21/14, $8,656,641 US Treasury Notes, 0.750% to 4.250% due 08/15/13 to 11/15/13; (value—$49,745,135); proceeds: $48,769,014 (cost—$48,769,000)	48,769,000		48,769,000
	Shares
Investment of cash collateral from securities loaned — 1.98%
Money market fund — 1.98%
UBS Private Money Market Fund LLC3 (cost—$5,149,647)	5,149,647		5,149,647
Total investments (cost—$261,643,268)13 — 103.07%			268,560,021
Liabilities in excess of other assets — (3.07)%			(7,992,323	)
Net assets — 100.00%			260,567,698
Aggregate cost for federal income tax purposes was substantially the same for book purposes and net unrealized appreciation consisted of:
Gross unrealized appreciation		$	16,788,659
Gross unrealized depreciation			(9,871,906	)
Net unrealized appreciation		$	6,916,753

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Futures contracts

Number of		Expiration		Current	Unrealized
contracts		date	Cost ($)	value ($)	depreciation ($)
Index futures buy contracts:
238	S&P 500 E-Mini Index Futures	June 2012	16,266,051	15,579,480	(686,571	)
			Proceeds ($)
US Treasury futures sell contracts:
49	US Treasury Note 10 Year Futures	September 2012	6,500,860	6,562,937	(62,077	)
					(748,648	)

The Fund calculates its net asset value based on the current market value for its portfolio securities. The Fund normally obtains market values for its securities from independent pricing sources. Independent pricing sources may use last reported sale prices, official market closing price, current market quotations or valuations from computerized “matrix” systems that derive values based on comparable securities. Securities traded in the over-the-counter (“OTC”) market and listed on The Nasdaq Stock Market, Inc. (“NASDAQ”) normally are valued at the NASDAQ Official Closing Price. Other OTC securities are valued at the last bid price available prior to valuation. Securities which are listed on US and foreign stock exchanges normally are valued at the market close, the last sale price on the day the securities are valued or, lacking any sales on such day, at the last available bid price. In cases where securities are traded on more than one exchange, the securities are valued on the exchange designated as the primary market by UBS Global Asset Management (Americas) Inc. (“UBS Global AM”). If a market value is not available from an independent pricing source for a particular security, that security is valued at fair value as determined in good faith by or under the direction of the Trust’s Board of Trustees (the “Board”). Various factors may be reviewed in order to make a good faith determination of a security’s fair value. These factors include, but are not limited to, the type and cost of the security; contractual or legal restrictions on resale of the security; relevant financial or business developments of the issuer; actively traded similar or related securities; conversion or exchange rights on the security; related corporate actions; and changes in overall market conditions. If events occur that materially affect the value of securities (particularly non-US securities) between the close of trading in those securities and the close of regular trading on the New York Stock Exchange, the securities are fair valued.

The amortized cost method of valuation, which approximates market value, generally is used to value short-term debt instruments with sixty days or less remaining to maturity, unless the Board determines that this does not represent fair value. Investments in open-end investment companies are valued at the daily closing net asset value of the respective investment company. Futures contracts are generally valued at the settlement price established each day on the exchange on which they are traded. Swaps are marked to market daily based upon values from third party vendors or quotations from market makers to the extent available. In the event that market quotations are not readily available or deemed unreliable, the swap is valued at fair value as determined in good faith by or under the direction of the Board.

In May 2011, FASB issued Accounting Standards Update (“ASU”) No. 2011-04 “Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in US GAAP and International Financial Reporting Standards (“IFRS”)” (“ASU 2011-04”). ASU 2011-04 includes common requirements for measurement of and disclosure about fair value between US GAAP and IFRS. ASU 2011-04 will require reporting entities to disclose the following information for fair value measurements categorized within Level 3 of the fair value hierarchy: quantitative information about the unobservable inputs used in the fair value measurement, the valuation processes used by the reporting entity and a narrative description of the sensitivity of the fair value measurement to changes in unobservable inputs and the interrelationships between those unobservable inputs. In addition, ASU 2011-04 will require reporting entities to make disclosure about amounts and reasons for all transfers in and out of Level 1 and Level 2 fair value measurements. The new and revised disclosures are effective for interim and annual reporting periods beginning after December 15, 2011. At this time, management is evaluating the implications of ASU 2011-04 and its impact on the financial statements.

In December 2011, FASB issued ASU No. 2011-11 “Disclosures about Offsetting Assets and Liabilities” (“ASU 2011-11”). These disclosures are intended to help investors and other financial statement users to better assess the effect or potential effect of offsetting arrangements on a company’s financial position. They also improve transparency in the reporting of how companies mitigate credit risk, including disclosure of related collateral pledged or received. In addition ASU 2011-11 facilitates comparison between those entities that prepare their financial statements on the basis of US GAAP and those entities that prepare their financial statements on the basis of IFRS. ASU 2011-11 requires entities to: disclose both gross and net information about both instruments and transactions eligible for offset in the financial statements; and disclose instruments and transactions subject to an agreement similar to a master netting agreement. ASU 2011-11 is effective for fiscal years beginning on or after January 1, 2013, and interim periods within those annual periods. At this time, management is evaluating the implications of ASU 2011-11 and its impact on the financial statements.

US generally accepted accounting principles (“GAAP”) requires disclosure surrounding the various inputs that are used in determining the value of the Fund’s investments. These inputs are summarized into the three broad levels listed below:

Level 1 — Unadjusted quoted prices in active markets for identical investments.

Level 2 — Other significant observable inputs, including but not limited to, quoted prices for similar investments, interest rates, prepayment speeds and credit risks.

Level 3 — Unobservable inputs inclusive of the Fund’s own assumptions in determining the fair value of investments.

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

The following is a summary of the fair valuations according to the inputs used as of May 31, 2012 in valuing the Fund’s investments:

	Unadjusted quoted
	prices in active
	markets for identical		Other significant	Unobservable
	investments		observable inputs	inputs
	(Level 1) ($)		(Level 2) ($)	(Level 3) ($)	Total ($)
Common stocks	139,141,175		—	—	139,141,175
Preferred stock	—		4,287	—	4,287
Investment company	—		10,696,010	—	10,696,010
Warrants	—		—	27	27
US government obligations	—		22,106,911	—	22,106,911
Mortgage & agency debt securities	—		17,031,996	—	17,031,996
Collateralized mortgage obligations	—		1,259,342	—	1,259,342
Commercial mortgage-backed securities	—		2,286,527	—	2,286,527
Corporate bonds	—		21,929,915	59	21,929,974
Non-US government obligations	—		185,125	—	185,125
Repurchase agreement	—		48,769,000	—	48,769,000
Investment of cash collateral from securities loaned	—		5,149,647	—	5,149,647
Futures contracts	(748,648	)	—	—	(748,648	)
Total	138,392,527		129,418,760	86	267,811,373

The following is a rollforward of the Fund’s investments that were valued using unobservable inputs (Level 3) for the nine months ended May 31, 2012:

	Preferred			Corporate
	stock ($)		Warrants ($)	bond ($)	Total ($)
Beginning balance	23		27	—	50
Purchases	—		—	—	—
Sales	(23,320	)	—	—	(23,320	)
Accrued discounts/(premiums)	—		—	—	—
Total realized gain/(loss)	23,297		—	—	23,297
Net change in unrealized appreciation/depreciation	—		—	—	—
Transfers into Level 3	—		—	59	59
Transfers out of Level 3	—		—	—	—
Ending balance	—		27	59	86

The change in unrealized appreciation/depreciation relating to the Level 3 investments held at May 31, 2012 was $(1,524). Transfers into Level 3 represent the value at the end of the period. At May 31, 2012, a corporate bond was transferred from Level 2 to Level 3 as the valuation is based on a fair valuation approved by the valuation committee based on unobservable inputs.

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

Issuer breakdown by country or territory of origin

	Percentage of total investments (%)
United States		96.4
Cayman Islands		0.8
Curacao		0.6
Bermuda		0.4
Canada		0.4
Switzerland		0.3
United Kingdom		0.3
Israel		0.2
Panama		0.2
Mexico		0.2
Luxembourg		0.1
Ireland		0.1
Total		100.0

For more information regarding the Fund’s other significant accounting policies, please refer to the Fund’s semiannual report to shareholders dated February 29, 2012.

Fund footnotes

*	Non-income producing security.
**	On September 7, 2008, the Federal Housing Finance Agency placed the Federal National Mortgage Association and the Federal Home Loan Mortgage Corporation into conservatorship, and the US Treasury guaranteed the debt issued by those organizations.
1	Security, or a portion thereof, was on loan at May 31, 2012.
2	Cumulative preferred stock. The next call date is July 27, 2012.
3	Investment in affiliated investment company. The table below details the Fund’s transaction activity in affiliated issuers for the nine months ended May 31, 2012. The advisor earns a management fee from UBS Credit Bond Relationship Fund and UBS Private Money Market Fund LLC.

		Purchases	Sales
		during the	during the		Change in net		Net income earned
		nine months	nine months	Net realized	unrealized		from affiliate for the
	Value at	ended	ended	gain	appreciation	Value at	nine months ended
Security description	08/31/11 ($)	05/31/12 ($)	05/31/12 ($)	05/31/12 ($)	05/31/12 ($)	05/31/12 ($)	05/31/12 ($)
UBS Credit Bond Relationship Fund	10,951,259	—	900,000	104,745	540,006	10,696,010	—
UBS Private Money Market Fund LLC	11,342,957	37,983,081	44,176,391	—	—	5,149,647	996

UBS U.S. Allocation Fund
Schedule of investments — May 31, 2012 (unaudited)

4	Illiquid security representing less than 0.00% of net assets as of May 31, 2012.
5	Security is being fair valued by a valuation committee under the direction of the board of trustees.
6	Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933. These securities, which represent 2.17% of net assets as of May 31, 2012, are considered liquid and may be resold in transactions exempt from registration, normally to qualified institutional buyers.
7	Variable or floating rate security. The interest rate shown is the current rate as of May 31, 2012 and changes periodically.
8	Step bond that converts to the noted fixed rate at a designated future date.
9	Bond interest in default.
10	PIK — Payment-in-kind security. Income may be paid in cash or additional notes, at the discretion of the issuer.
11	Security called in full on February 16, 2011. Position represents remaining escrow balance expected to be received upon finalization of call premium.
12	Perpetual bond security. The maturity date reflects the next call date.
13	Includes $5,072,590 of investments in securities on loan, at value plus accrued interest and dividends, if any.

Fund acronyms

ADR	American Depositary Receipt
BDC	Business Development Company
FDIC	Federal Deposit Insurance Corporation
MTN	Medium Term Note
OEM	Original Equipment Manufacturer
REMIC	Real Estate Mortgage Investment Conduit
OJSC	Open Joint Stock Company
TBA	(To Be Announced) Security is purchased on a forward commitment basis with an approximate principal amount (generally +/- 1.0%) and no definite maturity date. The actual principal amount and maturity date will be determined upon settlement when the specific mortgage pools are assigned.

Item 2. Controls and Procedures.

(a)

The registrant’s principal executive officer and principal financial officer have concluded that the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (“Investment Company Act”)) are effective based on their evaluation of these controls and procedures as of a date within 90 days of the filing date of this document.

(b)

The registrant’s principal executive officer and principal financial officer are aware of no changes in the registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act) that occurred during the registrant’s last fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 3. Exhibits.

(a) Certifications of principal executive officer and principal financial officer of registrant pursuant to Rule 30a-2(a) under the Investment Company Act are attached hereto as Exhibit EX-99.CERT.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

UBS Investment Trust

By:	/s/ Mark E. Carver
	Mark E. Carver
	President
Date:	July  30, 2012

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By:	/s/ Mark E. Carver
	Mark E. Carver
	President
Date:	July  30, 2012
By:	/s/ Thomas Disbrow
	Thomas Disbrow
	Vice President and Treasurer
Date:	July  30, 2012