The acquisition of HealthSpring, Nashville, by Cigna Corp. has cleared antitrust review by the Federal Trade Commission, according to a joint news release from the two insurers.

Bloomfield, Conn.-based Cigna agreed last month to pay $3.8 billion, or $55 a share, in an all-cash deal to acquire HealthSpring, which operates Medicare Advantage plans in 11 states.

Clearing the review by the FTC under the Hart-Scott-Rodino Antitrust Improvements Act is one of the closing conditions for the deal, according to the release. Others include approval by HealthSpring shareholders and state regulatory approvals. The companies still expect to close the deal during the first half of 2012.