SUNDERLAND are closing in on their first signing of the summer after officially making an eight figure bid for West Ham United striker Diafra Sakho.

The Hammers are ready to cash in on the player they bought for £4m when Sam Allardyce was in charge two years ago – and the Black Cats have tabled a bid of around £11m.

Sakho has impressed during his time in the Premier League and Sunderland had initially been quoted a fee in the region of £15m when they first asked.

Despite hopes of landing him for less than £10m, Allardyce has learned that discussions have been encouraging with West Ham and an agreement could soon be reached.

Slaven Bilic, the Hammers' boss, is publicly claiming he would like to keep him, although he is looking at adding his own striker this summer and has made a £20m-plus offer for Lyon’s Alexandre Lacazette.

Bilic was infuriated with Sakho in April when the player is understood to have withdrawn from the squad to face Arsenal under mysterious circumstances, having learned he would not be starting.

There was also a four-letter outburst on social media, which was claimed to relate to personal problems rather than his omission, but West Ham are still happy to listen to offers.

And with Allardyce still a big fan, and close to the player’s representatives, he has made a move with Sakho likely to be attracted by the prospect of teaming up with his former boss again.

The 26-year-old still managed seven goals during a season troubled by injury at Upton Park and he is likely to find opportunities limited further when West Ham start the new campaign at the Olympic Stadium.

He has scored 15 goals in 43 appearances since joining from Metz in the summer of 2014. Before that he had found the net 44 times in 114 games for the French club, having moved there from Dakar when he was 16.

Sakho would provide Sunderland with the extra power up front having finished the season with just Jermain Defoe really to call on to lead the line. Dame N’Doye, who struggled to make an impact, has returned to Trabzonspor following his loan, while Steven Fletcher and Danny Graham are to become free agents.

That would leave Allardyce with just Defoe and Fabio Borini as out-and-out strikers ahead of-pre-season, with even Borini seen more as a wide player along with Duncan Watmore by the Sunderland boss.

Even if he is successful in bringing in Senegalese striker Sakho, Allardyce is still in the market for more forwards and Swansea pair Andre Ayew and Bafetimbi Gomis are known to be under consideration.