The head of Sony's in-house game studio and one of its longest serving executives, Phil Harrison, will resign from the company at the end of February, Sony Computer Entertainment said Monday.

No reason was given for the move which will see Kaz Hirai, president of Sony Computer Entertainment (SCE), take on Harrison's duties in addition to his current job running the entire gaming unit.

Harrison has been at Sony since 1992, when he joined Sony Electronics Publishing. The company was a forerunner to Sony Computer Entertainment (SCE), which was formed when the PlayStation business was launched, and Harrison was one of a number of executives who played a key part in getting the business off the ground and pushing consumer adoption of the PlayStation, PlayStation 2, PlayStation Portable and, most recently, the PlayStation 3.

As president of SCE Worldwide Studios Harrison has been responsible for Sony's in-house games software operations.

"It is sad to see him departing from SCE, but I wish to express my gratitude for his many invaluable contributions and also wish Phil the very best of luck in his future endeavors," Kaz Hirai said in a statement announcing the resignation.