Sunderland boss Roy Keane has continued his summer spending by completing the signing of Bolton forward El-Hadji Diouf for an undisclosed fee.The 27-year Senegal international has agreed a four-year deal with the Black Cats after spending four seasons at the Reebok Stadium.

Diouf becomes Keane's fifth signing of the summer following the arrivals of Teemu Tainio, Nick Colgan, David Meyler and Pascal Chimbonda.

Keane was eager to bolster his attacking options ahead of the start of the Premier League season and the versatile Diouf is able to play on the wing or as a deep lying forward.

Diouf began his career with Sochaux and then had spells at Rennes and Lens before a £10million switch to Liverpool after impressing at the 2002 World Cup.

After a bright start at Anfield he struggled to live up to expectations and was sent on loan to Bolton in 2004, before a permanent switch to Wanderers -where he has since rejuvenated his career.

Diouf's time in English football has not been short of controversy and the most high-profile incident was when he spat at a Celtic fan in a UEFA Cup tie while at Liverpool.

But despite his controversial past Keane has no qualms about signing a player he believes other clubs "love to hate" if he can improve the quality in his squad.

"El-Hadji is a great signing for us and we're thrilled to get him," Keane said.

"He has bags of Premier League and international experience, which is exactly what we have been targeting this summer.

"El-Hadji has always been the kind of player opposition teams and supporters love to hate, a thorn in the side, and that's why we're delighted to now have him in our squad.

"Our coach, Ricky Sbragia, has also worked very closely with him and speaks extremely highly of him, so we're looking forward to working with El-Hadji, I think he's a signing that will excite our supporters."

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