The London club were running out of patience, after comments made by his brother claiming they are 'using' him.
West Ham have completed the sale of Marko Arnautovic to Shanghai SIPG for £22.4m (€25m), according to Sky Sports.
The 30-year-old passed a medical with the Chinese Super League side over the weekend, with the deal expected to be made official early this week.
West Ham decided to accept a “terrible deal” for Arnautovic, because everyone “wants him out”.
The London club were running out of patience, after comments made by his brother claiming they are “using” him.
The Austrian striker scored 21 goals in 59 Premier League matches in his two seasons at the club since arriving from Stoke City.
Arnautovic had asked to leave in January, but ended up signing a contract extension.
The new deal saw his wages rise by 20% to £120,000 a week, including a £40m release clause, which expired on June 14.