Nokia said on Thursday it had promoted Henry Tirri to chief technology officer after his predecessor Richard Green left the mobile phone company.

In June, Nokia said Green had taken indefinite leave for personal reasons, while media reports said he had disagreed with new chief executive Stephen Elop's smartphone strategy.

Tirri, who joined Nokia in 2004 and was previously head of its research center, will be based in Sunnyvale, California instead of the company's headquarters in Espoo, Finland.

Green, who was appointed to the CTO job in 2010, will be returning to the United States to pursue new opportunities, Nokia said.