UPDATE 1-Cigna raises full-year profit forecast again

Nov 1 (Reuters) - Health insurer Cigna Corp's quarterly profit more than doubled as its acquisition of Medicare specialist HealthSpring drove growth in premiums and fees, prompting the company to raise its full-year profit outlook for the third time this year.

Premium and fees revenue at its health care segment jumped 51 percent, driven by contributions from HealthSpring, which Cigna acquired for $3.8 billion earlier this year.

Health insurers are facing a healthcare overhaul as the government tries to rein in reimbursements, and have been on an aggressive acquisition spree to gain scale and market share.

Recent big deals include UnitedHealth Group Inc's $4.9 billion buy of a majority stake in Brazilian health insurer Amil Participacoes SA and Aetna Inc's takeover of Coventry Health Care Inc for $5.6 billion.

Cigna's total third-quarter revenue rose 31 percent to $7.4 billion. Revenue at its international segment rose 22 percent, and disability and life segment revenue increased 9 percent.

The insurer now expects full-year adjusted earnings of $5.70 to $5.90 per share, up from its prior forecast of $5.25 to $5.60 per share in August.

The company's strong results follow the market-topping profits posted by rivals UnitedHealth and Aetna last month.

Third-quarter net income rose to $466 million, or $1.61 per share, in the third quarter, from $183 million, or 67 cents per share, a year earlier.

Excluding items, the company earned $1.69 per share, handily beating analysts' estimates of $1.36, according to Thomson Reuters I/B/E/S.

Shares of Cigna, which has a market capitalization of $14.71 billion, closed at $51 on Wednesday on the New York Stock Exchange.