West Ham break transfer record for Ayew

Ghana striker Andre Ayew has joined West Ham United from Premier League rivals Swansea City for a club-record transfer fee of STG20.5 million ($A35 million).

The 26-year-old has agreed a three-year contract with the option for an additional two years.

Ayew played a pivotal role in steering Swansea away from relegation last season, netting 12 times in 34 starts as Francesco Guidolin's side finished 12th in the table.

He leaves Swansea one year after joining on a free transfer from Olympique Marseille.

"I am very proud and happy to be at this magnificent club. I hope to make the people very happy here," Ayew told West Ham's website.

"The club have a lot of ambition and have a great manager (Slaven Bilic). They want to become a bigger club every year and with the new (Olympic) stadium and a new training ground, you can feel they are moving on to another level.

"I want to train hard, do my job and show that I deserve to play for West Ham United. I want to give back to the manager and the fans the confidence they are showing me."

Ayew, who has won 67 caps for Ghana, becomes the London team's fifth close-season signing, following winger Sofiane Feghouli, defender Havard Nordtveit, striker Toni Martinez and left back Arthur Masuaku.

West Ham, who finished seventh last season, open their league campaign with a London derby against Chelsea next Monday.