Nokia has confirmed that CTO Rich Green, who walked out over the summer, won’t be returning to work. Instead, he will be replaced from Thursday by Henry Tirri, who previously headed up Nokia’s research facility.

Green, who was appointed CTO in May 2010, took an extended leave of absence one year later after falling out with new president and CEO over the Finnish firm’s tech strategy. Green, a veteran of Sun Microsystems and a mover and shaker in the Java world, was sidelined when the firm outsourced development of the floundering Symbian operating system to consultancy and outsourcing firm Accenture, while MeeGo was sidelined in favour of Microsoft Windows Phone.

Green will be returning full time to the US to pursue new opportunities, Nokia said.

Tirri assumes responsibility for the CTO organisation, reporting directly to Elop. Previously, he was Head of Nokia Research Centre (NRC), after joining Nokia in 2004 as a Research Fellow before leading NRC Systems Research laboratory in 2007.