INVESTMENT IN TRANSMISSION AFFILIATES

We own approximately 60% of ATC, a for-profit, transmission-only company regulated by the FERC for cost of service and certain state regulatory commissions for routing and siting of transmission projects. We also own approximately 75% of ATC Holdco, a separate entity formed in December 2016 to invest in transmission-related projects outside of ATC's traditional footprint. The following tables provide a reconciliation of the changes in our investments in ATC and ATC Holdco:



	Three Months Ended March 31, 2019
(in millions)	ATC		ATC Holdco			Total
Balance at beginning of period	$	1,625.3	$	40.0		$	1,665.3
Add: Earnings (loss) from equity method investment	36.5		(0.4		)	36.1
Add: Capital contributions	3.0		0.4			3.4
Less: Distributions	34.2		—			34.2
Balance at end of period	$	1,630.6	$	40.0		$	1,670.6



	Three Months Ended March 31, 2018
(in millions)	ATC		ATC Holdco			Total
Balance at beginning of period *	$	1,515.8	$	37.6		$	1,553.4
Add: Earnings (loss) from equity method investment	33.4		(0.6		)	32.8
Add: Capital contributions	12.0		0.8			12.8
Less: Other	0.1		—			0.1
Balance at end of period	$	1,561.1	$	37.8		$	1,598.9


*	Distributions of $39.9 million, received in the first quarter of 2018, were approved and recorded as a receivable from ATC in other current assets at December 31, 2017.

We pay ATC for network transmission and other related services it provides. In addition, we provide a variety of operational, maintenance, and project management work for ATC, which is reimbursed by ATC. We are required to pay the cost of needed transmission infrastructure upgrades for new generation projects while the projects are under construction. ATC reimburses us for these costs when the new generation is placed in service.

In connection with UMERC's construction of the new natural gas-fired generation in the Upper Peninsula of Michigan, UMERC was required to pay ATC for the costs of the transmission infrastructure upgrades needed for the new generation. ATC owns these transmission assets and will reimburse UMERC for these costs in 2019, as the new generation has now been placed in service. At March 31, 2019 and December 31, 2018, the amounts to be reimbursed to UMERC related to the transmission infrastructure upgrades were $32.4 million and $29.4 million, respectively.

The following table summarizes our significant related party transactions with ATC:



	Three Months Ended March 31
(in millions)	2019		2018
Charges to ATC for services and construction	$	4.0	$	4.6
Charges from ATC for network transmission services	87.1		84.5

Our balance sheets included the following receivables and payables for services received from or provided to ATC:



(in millions)	March 31, 2019		December 31, 2018
Accounts receivable for services provided to ATC	$	2.0	$	3.4
Accounts payable for services received from ATC	29.0		28.2

Summarized financial data for ATC is included in the following tables:



	Three Months Ended March 31
(in millions)	2019		2018
Income statement data
Operating revenues	$	177.7	$	165.4
Operating expenses	90.4		84.9
Other expense, net	28.8		27.6
Net income	$	58.5	$	52.9



(in millions)	March 31, 2019		December 31, 2018
Balance sheet data
Current assets	$	87.8	$	87.2
Noncurrent assets	5,012.7		4,928.8
Total assets	$	5,100.5	$	5,016.0

Current liabilities	$	571.1	$	640.0
Long-term debt	2,164.1		2,014.0
Other noncurrent liabilities	288.6		295.3
Shareholders' equity	2,076.7		2,066.7
Total liabilities and shareholders' equity	$	5,100.5	$	5,016.0