The former Bury striker handed in a transfer request after being left out of the side against Rotherham United on the opening day of the season.
Kazim-Richards, 20 was a target for Sheffield Wednesday last season and last week Championship side Barnsley saw their bid rejected; it now looks as though an undisclosed bid from Sheffield United has been accepted and he will sign on Wednesday.
"Colin made it clear to me he no longer wished to play for Brighton; as a result we have reluctantly accepted the bid from Sheffield United," said Brighton boss Mark McGhee..
"I am really disappointed and I feel personally let down by Colin. We gave him the chance to get out of Bury and I don't think he's repaid us for that, we felt Colin could have built his career here at Brighton.''
Meanwhile the Seagulls have completed the signing of former Blades Midfielder Georges Santos who was released by Queens Park Rangers this summer.