XO Holdings, Inc. President and CEO Carl J. Grivner has resigned, the telecommunications company announced Friday.

Herndon, Va.-based XO has not named a new leader and the company said its board of directors is conducting a search to identify a new chief executive.

XO said it will consider candidates inside and outside the company.

My decision to leave the company to pursue other opportunities is a personal and difficult one,” said Grivner, who had led XO for the last eight years and also serves as a director.

The companys board has established an executive committee comprised of three individuals to manage the companys operations for the time being.

One of those individuals, XO Chief Financial Officer Laura W. Thomas, will oversee all corporate functions and business units other than the Business Services and Carrier Services units.

Grivner has agreed to assist the company during a transition period.

XO announced Grivners resignation about a week after the company reported its annual earnings. 

The company reported an annual net loss of $11.8 million on revenues of $1.529 billion.

In January XO announced that it formed a special committee from its board of directors to evaluate a proposal by an affiliate of billionaire Carl Icahn ACF Industries Holding Corp. to acquire the telecom provider for 70 cents per share in cash.  Icahn is the chairman of XO Holdings, and through ACF Holding and its affiliates, already holds the majority of XOs common stock.

In a statement, Icahn wished Grivner well and put a plug in for XO, whose revenues were basically flat in 2010.

We wish Carl the best in his future endeavors and thank him for his contributions to the company,” Icahn said. We are fortunate to have one of the deepest management teams and one of the strongest balance sheets in the telecommunications industry with approximately $1 billion in equity and no outstanding debt.”