(Adds earnings outlook, background)
May 6 (Reuters) - Hospital operator Community Health Systems Inc reported a first-quarter net loss on Tuesday, weighed down by the costs of acquiring smaller rival Health Management Associates.
Community Health, the second-largest U.S. for-profit hospital operator, also narrowed its forecast for full-year earnings at the lower end of its prior range.
Harsh winter weather in key markets and a milder flu season dragged on first-quarter results, but implementation of the Affordable Care Act is starting to have a positive impact on operations, Community Health Chief Executive Wayne Smith said.
Most hospital companies in the first quarter have reported early signs President Barack Obama's healthcare law is bringing more insured patients through their doors, but said it is too early to draw conclusions about the overall impact.
No. 3 hospital chain Tenet Healthcare Corp said on Tuesday the number of newly insured patients it has treated ramped up in February through April.
Community Health, which completed its acquisition of Health Management Associates in January, posted a first-quarter loss of $112 million, or $1.04 a share, compared with net income of $79 million, or 86 cents a share, a year ago.
Excluding one-time items, the Franklin, Tennessee-based company said it earned 27 cents a share from continuing operations in the quarter.
On that basis, analysts were expecting a profit of 19 cents a share, according to Thomson Reuters I/B/E/S.
Net operating revenue rose 28 percent to $4.2 billion.
But at hospitals it has operated for at least one year, net operating revenue declined 4 percent from a year ago as patient admissions decreased 8.1 percent.
Community Health said it now expects full-year earnings from continuing operations of $2.70 to $3.20 a share. In February, the company forecast 2014 earnings in a range of $2.70 to $3.75 a share.
Community Health shares closed 1.1 percent lower at $39.42 Tuesday on the New York Stock Exchange. (Reporting by Susan Kelly in Chicago; Editing by Bernard Orr and Andre Grenon)