"I feel it would be in the best interests of myself and the club to move on. It is clear I am not in the manager's plans," said Angel.
"I'm disappointed with the way I'm being treated. I came here to play first-team football and I don't think I have been given the opportunity this season under Graham Taylor."
Angel has scored just 20 goals in all competitions since joining Villa in January 2001 and just one League goal this season.