Central European Media Enterprises Ltd. CETV, -0.25% said Monday its board has decided to review its strategic alternatives, including a possible sale of the company. The media and entertainment company operates in five Central and Eastern European markets with TV channels in Bulgaria, the Czech Republic, Romania, the Slovak Republic and Slovenia. AT&T Inc. T, +0.25% the company's biggest shareholder, supports the review, the company said in a statement. U.S.-listed shares were halted premarket for the news, but have fallen 15% in the last 12 months, while the S&P 500 SPX, +0.16% has gained 8%.