An activist investor is calling on Olive Garden's parent company Darden Restaurants to consider looking for a new CEO.

Barington Capital Group says it sent a letter to Darden's board saying it was concerned by the company's "rapidly deteriorating financial performance" under chief executive Clarence Otis.

As it fights to keep up with a rapidly changing restaurant industry, Darden has said it will spin off or sell its struggling Red Lobster chain and focus on fixing Olive Garden.

But Barington has objected to the plan, saying Olive Garden should be separated from the company's more successful specialty restaurant group as well.

A representative for Darden Restaurants Inc. wasn't immediately available for comment.

Otis has been CEO since 2004 and chairman since 2005.