Dean Ashton has agreed personal terms with West Ham and will sign after undergoing a medical at Upton Park.
Ashton earlier revealed the chance to return to the Premiership was 'too good to turn down'' after the Hammers agreed a £7.25million deal with Norwich for the England Under-21 international.
Ashton met West Ham to negotiate personal terms today and will undergo a medical check before completing the move tomorrow.
West Ham will pay £7million plus a conditional £250,000 while a 15% sell-on clause has also been negotiated.
Ashton said: 'I have had a great year at Norwich and would like to sincerely thank the fans and everyone I have worked with at Carrow Road.
'West Ham are a big club, I am ambitious and at the end of the day the chance of a swift step up to the Premiership is too good to turn down.
'I spoke to Nigel and the board and told them I wanted to pursue this opportunity.''
He added on the club's website: 'I'd like to thank Norwich for understanding that and allowing myself and my representative to talk to West Ham.''
Norwich chief executive Neil Doncaster revealed a bid was received yesterday and accepted following a meeting between the board and manager Nigel Worthington after the defeat by Watford.
Ashton's former club Crewe will receive £1.5million up front due to a sell-on clause included when they sold him to Norwich for £3million a year ago.
Worthington also believes the deal is in the best interests of all parties.
'We're always committed to trying to keep our best players at the club, but the size of the bid coupled, with Dean's desire to make the move happen meant that after talking it through with the board and the lad himself, we've decided to accept this offer,'' he said.
'If the move goes through, I'd like to place on record my thanks to Dean for his contribution and his professionalism during his time at Norwich and wish him all the very best in his future career.''
Doncaster, who along with Worthington has been forced to fend off constant speculation about Ashton's future, said: 'We received a bid worth a total of £7.25million from West Ham, plus a sell-on.
'That's by far the largest bid we have received and a club record by some distance, and after full consultation with the manager, the board and the player himself, it was decided it was in the best long-term interests of the club to accept this offer.''
The large transfer fee will surprise many - Wigan boss Paul Jewell baulked at Norwich's demand for 'silly money'' before Christmas - but West Ham managing director Paul Aldridge believes it will be money well spent as the Hammers look to consolidate in the Premiership.
He told the club's website: 'Alan Pardew has identified Dean as a player who can play a key role in helping the club to reach a new level, and we have therefore worked extremely hard to ensure that the transfer goes ahead.
'We are paying a club record transfer fee for Dean because we feel that, at 22, he represents an investment that can benefit West Ham for years to come at the highest level.''