West Ham have confirmed the resignation of chief executive Scott Duxbury.
The move comes as a result of this month's takeover of the club by David Gold and David Sullivan, with Duxbury effectively being squeezed out when the owners brought in their former Birmingham colleague Karren Brady as vice-chairman.
Duxbury said in a statement: "I am proud of my work at West Ham United, but feel the time is right for me to pursue other opportunities.
"I wish Mr Sullivan, Mr Gold and Karren great success in driving this wonderful football club forward, and I know under their stewardship the club will prosper.
"Thank you to all the supporters who have kept faith with the club through good and bad times."
Duxbury joined West Ham as the club's in-house lawyer under chairman Terry Brown, and was subsequently promoted to chief executive by chairman Eggert Magnusson after the club was bought by an Icelandic group.
However, his time running the club was blighted by controversy, not least because of his role in signing Carlos Tevez in a deal which breached Premier League rules and subsequently cost the club more than £30million in fines and compensation payments.
Brady said: "We thank Scott for his valued contribution and wish him every success in the future."