West Ham United Football Club (WHU) will be the new anchor tenant of the London Olympic Stadium following the government's agreement to contribute a further £25m towards converting the venue.
WHU was chosen as the preferred bidder for the tenancy in December 2012 but the signing of the deal was dependent on a number of financial and commercial terms being agreed upon.
It is believed that as part of the negotiations, WHU has also agreed to increase its contribution towards the conversion project from £10m to £15m.
The deal means that the proposed conversion of the stadium - which involves reducing the seating capacity from 80,000 to around 55,000 to 60,000 - can now go ahead.
The redevelopment of the venue and the planned use of retractable seating will allow the stadium to operate as both an athletics and football arena.
WHU has signed a 99-year lease for the venue and is hoping to move into the stadium in time for the 2016-17 season.
Karren Brady, WHU vice chair said: "A capacity of at least 54,000 seats will place WHU among the top five attended clubs in the Premier League.
"In addition, we would be moving to one of the best connected stadiums in Europe, set in its own parkland with world class facilities. The move will provide an opportunity to improve our fortunes on every level including opening doors to new revenue streams."
