News Pushes Centris Shares Down 16.44%

Centris Group Inc. shares dropped 16.44% Thursday after HCC Insurance Holdings Inc. withdrew its offer to buy the Costa Mesa medical insurer.

Centris stock closed at $11.75, off $2.31 a share as 126,000 shares changed hands, more than double the daily volume over the last three months. Earlier in the session, the stock fell to $11.38 a share.

After the close of trading Wednesday, HCC withdrew its offer to pay about $143 million, or $13.25 a share, for the 92.2% of Centris it doesn’t own. HCC said it decided to end the pursuit because Centris management wouldn’t negotiate.

In rejecting the offer earlier Wednesday, Centris said the bid was “grossly inadequate.” Centris sells insurance that covers unexpected medical claims against employers that self-insure their employees’ health care.

Houston-based HCC is trying to expand its presence in the medical stop-loss insurance market. Buying Centris would have doubled its premiums in that business to about $450 million, making it the largest provider of such coverage.

HCC also sells aviation, marine and accident insurance. The company’s shares were off 19 cents to $19.25.