Billionaire investor Carl Icahn and his affiliates have picked up a 14.5 percent stake in petroleum refiner and marketer CVR Energy Inc., saying its shares were undervalued.

This makes Icahn and his affiliates the largest shareholders in the company, according to Thomson Reuters data.

The purchase price of the shares and call options was about $144.7 million, Icahn said in a filing with U.S. Securities and Exchange Commission.

The activist investor may initiate dialogue with the Texas-based company to discuss its business and strategic alternatives.

Shares of the company closed at $23.05 on Friday on the New York Stock Exchange.