The agreement should settle a long-running saga over the future of the stadium, built with 430 million pounds ($653 million) of public money and the centrepiece of last summer's London Games.
But Barry Hearn owner of nearby Leyton Orient told Talk Sport this moring that he will continue with his fight to have the process over turned in the High Court as he belives his club should be able to share the facility.
Hearn said he feared the move by West Ham could put them out of business, but that he will abide by the High Court's decision. He did say that he thought today's announcement was premature in the light of the Court hearing.
London mayor Boris Johnson was more optimistic saying:"Through this deal with West Ham United FC, we are defying the gloomsters who predicted this landmark would become a dusty relic,"
West Ham, who have won the FA Cup three times, have signed a 99-year agreement that will make them the main tenant of the stadium and only around three miles from the smaller Boleyn Ground where they have played for more than a century.
Johnson said conversion work could possibly be staggered to allow the stadium to host rugby World Cup matches before West Ham move in.
"We are looking with great interest at the rugby World Cup in 2015. It would be great if we could make that work," he told a news conference in a restaurant opposite the empty stadium.
West Ham plan to add a new roof to keep fans dry during the winter, executive boxes and retractable seating to go over the running track to let supporters get close to the action.
The running track will remain and the stadium will host the 2017 world athletics championships.
West Ham will contribute 15 million pounds towards the rebuilding work plus a share of naming rights income. The local council is providing 40 million pounds as a loan, while central government has offered up to 25 million pounds.
Former sports minister Richard Caborn called the West Ham deal "the biggest mistake of the Olympics."
"West Ham are basically getting a stadium costing more than 600 million pounds for just 15 million and a small amount in annual rent," he told British media.
Johnson defended the deal, saying it was a good investment for the taxpayer.
"It will deliver long-term revenues, and it will also help to regenerate part of east London and create thousands and thousands of jobs," he said.
The LLDC has also ensured that the taxpayer benefits from any increase in value of the club if owners David Gold and David Sullivan were to decide to sell it within the next 10 years.
The owners said they were committed to a club they bought in 2010. They see a larger stadium as a chance for West Ham, promoted last season, to compete with the top clubs in the Premier League.
"Our intention is to be at this football club until we die," said David Gold. "There is every possibility that we will hand over ownership of this great football club to our children."