PalmSource has acknowledged that it is entering a period of "leadership transition" after David Nagel stepped down as the mobile software firm's president, chief executive and director.

Nagel's departure was made effective yesterday, and PalmSource confirmed that Patrick McVeigh, currently senior vice president for worldwide licensing, has been named interim chief executive.

The board of directors has initiated a search for a permanent successor, and Nagel will remain at PalmSource in an "advisory role" through to mid-July.

Nagel previously served as a member of the board of Palm and was named chief executive and elected to the board of PalmSource in December 2001.

He headed up PalmSource when it was spun off from Palm in October 2003, and subsequently completed a public offering in April 2004. He also helped to complete the acquisition of China MobileSoft in January 2005.

Jean-Louis Gassée, chairman of the PalmSource board of directors, said: "We appreciate that David is staying on to ensure a smooth transition and wish him the best in his future ventures."

Patrick McVeigh joined PalmSource in February 2005 as senior vice president of worldwide licensing.

He is the former chief executive at Aliph Corporation, a developer of audio and speech technologies for mobile communications devices, prior to which he was chairman and chief executive at Omnisky Corporation.