Advanced Micro Devices Inc. appointed Lisa Su as president and chief executive officer, replacing Rory Read, as the semiconductor maker struggles to turn itself around.

The Sunnyvale, California-based company said in a statement Wednesday that the promotion of Su, 44, who had been chief operating officer, is effective immediately. Read, 52, who is also stepping down from the board, will remain with AMD through the end of the year in an advisory role, the company said. Read had been CEO since 2011.

AMD has been under pressure because of its rivalry with Intel Corp. Under Read, AMD was working to get more of its sales from markets where it doesn’t directly compete with the world’s largest chipmaker, such as game consoles and industrial and medical equipment.

While those initiatives have paid off by winning customers including Sony Corp. and Microsoft Corp., which have both based their newest video-game consoles on chips made by Read’s company, AMD’s earnings remain dependent on a shrinking personal-computer market where Intel has been faster to update its product lineup with better-performing processors.

The two companies are the only remaining makers of processors that are the main components of PCs. Intel has more than 80 percent of that market, according to researcher IDC.

Investors took the news negatively Wednesday. At about 6 p.m. in New York, AMD shares were down 6.7 percent at $3.06, after ending the regular session unchanged.