The value of the deal was not disclosed in a statement on Monday from West Ham, who offered no thanks for the Austria forward's 22 goals in two seasons.

The club's Twitter account message was even shorter: "Marko Arnautovic departs ."

British media reported the transfer fee was around STG22 million ($A39 million).

Relations between West Ham and Arnautovic have been tense since he sought a move to China in January, and got worse this offseason.

Arnautovic leaves despite signing a contract extension in late January.

The 30-year-old forward was a club record STG20 million signing from Stoke in 2017.

At Shanghai, Arnautovic will join up in attack with former Brazil internationals Hulk and Oscar.

Australian Associated Press