Nokia has announced that it has appointed Henry Tirri as the company’s permanent Chief Technology Officer (CTO), after the executive temporarily occupied the position after the resignation of Rich Green, who left the company “for personal reasons”.

The Nokia Group Executive Board member’s leave was confirmed by Nokia, saying it was due to medical reasons, but the company refrained from detailing the length of his absence or the reasons behind it. Two independent sources said at the time that Green’s leave would last at least until the end of the year, with it highly likely that he would not return to Nokia thereafter.

Today’s announcement confirms that fact, with a Nokia statement noting that Mr Green was no longer a member of the Nokia Leadership Team and would now return to the U.S to “pursue new opportunities”.

Henry Tirri will now take the position full time and report directly to Nokia CEO Stephen Elop:

Nokia announced today that Henry Tirri has been appointed executive vice president, Chief Technology Officer and a member of the Nokia Leadership Team, effective September 22, 2011. He reports directly to President and CEO Stephen Elop.

As Chief Technology Officer, Tirri assumes responsibility for the CTO organization, charged with setting Nokia’s technology agenda both now and in the future, and driving core innovation to enable business development opportunities.

Nokia was criticised for its dedication to the Symbian operating system, with it suggested that Green’s decision to leave the vendor may have been as a result of Nokia’s announcement that it was to move away from the co-development of the MeeGo platform, an operating system that Green is reported to have wished to continue developing.

Nokia’s decision to abandon MeeGo came after the company signed a deal with Microsoft to incorporate Windows Phone into its devices.