Witter won the WBC crown by beating American DeMarcus Corley on points at London's Alexandra Palace in September.

The Bradford boxer, who has won 35 of his 38 fights, then made a successful defence of his title in January, when he stopped Mexican Arturo Morua in round nine.

But Harris, a former WBA champion at light welterweight, will be a tougher proposition.

"Harris is a top level operator," said Witter. "I hear the Americans are tipping him to do big things in the division."

Guyana-born Harris, 28, has fought 31 times, winning 28 of his bouts by KO but losing twice and drawing once.

One of his two defeats came to Carlos Maussa in 2005, with Harris suffering a shock KO in round seven to lose his WBA belt.

Colombian Maussa was subsequently stopped by Ricky Hatton.

Witter's promoter Mick Hennessy concluded terms on the deal with his counterpart Gary Shaw on Friday.

"This is a tough first mandatory fight, but that's how it should be," said Hennessy.

"Harris has regained the top form that was making people talk very highly of him a couple of years ago when he beat Oktay Urkal in his backyard and then Soulemane M'Baye.

"Both of these fighters go for the knockout, so I believe this is going to be an explosive fight."