J.C. Penney (NYSE: JCP) agreed to name William Ackman to its board of directors after the activist investor became the department store chain’s largest shareholder.

Ackman, the chief executive officer of hedge fund firm, Pershing Square Capital Management, has a 16.5 percent stake in Penney.

Steven Roth, chairman of Vornado Realty Trust (NYSE: VNO), will also join the board. Vornado owns about 9.9 percent of Penney.

In a related matter, three months after Pershing said it wanted to talk to Penney managers about the company’s performance, chief executive officer Myron Ullman announced plans to close down unprofitable and poorly-performing stores.

JCP will shut down retail shops in Georgia, Illinois and Iowa. The retail giant also plans to close 19 outlets stores over two years and will also close two call centers, as well as a custom-decorating fabrication facility.