Second-quarter earnings doubled from last year at Aetna ( AET), thanks to strong fee and membership gains and reduced costs.

The Hartford, Conn., health insurer earned $286.3 million, or $1.79 a share, in the three months ended June 30, up from earnings of $138.4 million, or 87 cents a share, last year. Excluding items, the company earned $1.77 a share in the most recent quarter. Revenue rose 9% to $4.9 billion.

Analysts surveyed by Thomson First Call had expected earnings of $1.66 a share on revenue of $4.87 billion. Looking ahead, Aetna expects operating earnings of $6.75 to $6.85 a share in the full year, up from previous guidance of $6.60 to $6.75 a share but below the consensus analyst estimate of $6.89 a share.

Within Aetna's largest segment, healthcare, operating earnings were $264 million in the second quarter of 2004 compared with $175.7 million last year. The company cited higher revenue from increased fees and premiums and higher medical membership, as well as falling costs. Total medical membership was 13.4 million at June 30, 2004, up from 13.3 million at March 31.