Conseco Inc. says its directors have adopted a measure that would keep large, hostile shareholders from reducing the value of the company’s net operating loss carryforwards.

Under Section 382 of the Internal Revenue Code, a shareholder owning 5% of more of a company’s stock could keep Conseco from applying past operating losses to future tax bills.

At Conseco, Carmel, Ind., the board has acted to discourage an individual or group from buying more than 5% of the company’s stock and gaining the ability to block tax loss carryforwards, the company says.

Under the new plan, the company will distribute 1 right for each share of common stock outstanding as of the close of business Jan. 30.

If an investor that already owns at least 5% of Conseco tries to increase its stake by more than 1 percentage point without seeking board approval, the rights will act to dilute the investor’s stake, Conseco says.

“The rights plan, similar to those adopted by other publicly held companies, is not intended for defensive or anti-takeover purposes, but to preserve stockholder value, and is in the best interests of Conseco’s stockholders,” Conseco Chief Executive James Prieur says in a statement.

Continuation of the rights plan must be approved by Conseco stockholders at the company’s next annual meeting, in May.

If the stockholders vote to continue the rights plan, the plan the will be effective until Jan. 20, 2012, unless terminated earlier by the board, Conseco says.