A managed care company says the turmoil in the investment markets could force it to make a big pension contribution this year.

Aetna Inc., Hartford, says it originally had expected its pension plans to generate about 15 cents in pension plan gains per share in 2008.

Now, because of the slump in the stock market, Aetna is expecting to incur about 39 cents in pension expenses per share this year, rather than to report any pension plan gains, the company says.

But Aetna still plans to report about $3.90 in operating earnings per share for 2008, in spite of increases in pension funding expenses, the company says.