UPDATE 2-Centene tops profit estimates on strength in Obamacare business

* Raises 2017 revenue forecast

* 3rd-qtr adj. EPS $1.35 vs. estimate $1.25 (Adds analyst comment, details on health benefits ratio)

Oct 24 (Reuters) - Health insurer Centene Corp's quarterly earnings beat analysts' estimates due to increased membership and growth in its Obamacare business, prompting the company to raise its 2017 revenue forecast.

The results come at an uncertain time for the health insurance industry, with U.S. President Donald Trump earlier this month saying that his administration would stop paying billions of dollars in subsidies that help insurers give discounts to low-income households.

Since then, Trump has alternately supported, and dismissed, an effort by Republican and Democratic senators that would reinstate the subsidies for two years until a broader replacement to the 2010 Affordable Care Act, commonly known as Obamacare, can be negotiated.

Centene said it expects an impact of 7-12 cents per share in the fourth quarter if the subsidies are not received.

Despite the uncertainty around subsidies, Centene seems full steam ahead on Obamacare, increasing marketing and business expansion costs, Piper Jaffray analyst Sarah James said.

"Our county level analysis gives us confidence Centene will remain profitable in the 2018 exchanges."

Last month, the company said it would buy privately held Fidelis Care for $3.75 billion to enter New York, the second-largest managed-care state by membership in the United States, expanding its government-sponsored healthcare coverage.

Centene said net earnings attributable rose nearly 40 percent to $205 million, or $1.16 per share, in the third quarter ended Sept. 30.

Excluding items, the company earned $1.35 per share, beating the average analyst estimate of $1.25, according to Thomson Reuters I/B/E/S.

The company's total revenue rose nearly 10 percent to $11.90 billion. Analysts had expected revenue of $11.78 billion.

Centene's health benefits ratio, or the amount it spends on medical claims compared with its income from premiums, came in at 88 percent in the third quarter, compared with 87 percent a year earlier.

The ratio, which is closely watched by investors for increased medical costs and usage, was higher primarily due to new or expanded health plans, which initially operate at a higher health benefits ratio, and an increase in higher acuity members.

The company said it expects 2017 revenue in the range of $47.4 billion to $48.2 billion, up from its previous forecast of $46.4 billion to $47.2 billion. (Reporting by Ankur Banerjee in Bengaluru; Editing by Maju Samuel)