GUANGZHOU, May 22 (Xinhua) -- China Southern Airlines will start code-sharing with Finnish airline Finnair starting from June 1 on its Guangzhou-Helsinki route and part of its Europe-China flight network, the company said Wednesday.

Code-sharing, by which two airlines build partnership on selling tickets for flights operated by one another, is an effective way to improve route networks and expand market share.

Christian Lesjak, senior vice president of network and resource management of Finnair, said China was a key market in the global layout of Finnair.

The cooperation will allow passengers of China Southern Airlines, departing from Guangzhou, to transfer via Helsinki to Amsterdam, Copenhagen, London, Paris, Stockholm and other European cities, while Finnair passengers can transfer via Guangzhou to Chinese cities including Changsha, Chongqing, Hangzhou, Nanjing and Sanya.

China Southern Airlines' route network has been expanded to the Nordic region for the first time through the cooperation, said Wu Guoxiang, general manager of China Southern Airlines' international cooperation department.