Chipmaker Advanced Micro Devices announced the departure of three senior executives on Monday following recent layoffs and the appointment of a new CEO.

John Byrne, General Manager of AMD's Computing and Graphics Business Group is leaving, as are Chief Marketing Officer Colette LaForce and Chief Strategy Officer Raj Naik, the company said in a press release.

AMD has seen its stock market valuehalved since 2011 as the company lost market share to much-larger Intel Corp.

It has been expanding into new markets such as game consoles and low-power servers, but progress has been slower than demanded by Wall Street.

Lisa Su was promoted to Chief Executive Officer in October after joining the company in 2012 as senior vice president and general manager, global business units. She will take up Byrne's duties as AMD looks for a replacement, the company said.

The Computing and Graphics Business Group includes AMD's core business of processors for personal computers.

The changes are "part of implementing an optimal organization design and leadership team to further sharpen our execution and position AMD for growth," spokesman Drew Prairie said in an email.

AMD also said its board of directors approved retention awards for Chief Financial Officer Devinder Kumar and Chief Technology Officer Mark Papermaster.

Following Su's appointment as CEO, the timing of which surprised Wall Street, AMD announced it was cutting 7 percent of its workforce.

Shares of AMD were down 0.76 percent in extended trade after closing flat on Nasdaq. (Reporting by Noel Randewich; editing by Gunna Dickson)