Cigna Corp., the third-largest US health insurer, will now concentrate on its employee benefits' business after the sale of its property-and-casualty business to ACE Ltd. for $3.45 billion.

Cigna wants to increase its health insurance and employee retirement businesses through better marketing, technology, and if needed, through acquisitions, in the US and international markets, said spokesman Michael Monroe. It will also use the proceeds from the property-and-casualty sale to repurchase shares, he said.

Cigna, which evolved from the oldest property-and-casualty insurer in the US, has worked toward becoming a health insurer in the past five years. It's sold businesses that don't fit in its plans to become a one-stop shop for employee benefits.

"Health insurance has a much greater growth potential, but that comes with risks,'' said Greg Crawford, a Fox-Pitt Kelton Inc. analyst.

Cigna would use its own resources to increase its customer base, then look at acquisitions, Monroe said. He said acquisitions could include other health insurers or retirement benefits' providers.

"We would consider any acquisition that would expand our employee-benefit franchise,'' Monroe said. "That would include not just health care, but pension management or one of our other concentrations.'' Health insurance will make up about 70 percent of Cigna's business, while the remainder is largely the pension-management services.