Crossrail was today handed a £150 million Christmas present by Canary Wharf in a deal London Mayor Boris Johnson hailed as vital for the future of the London economy.

Canary Wharf Group, the developer and owner of much of Docklands, put the money towards the new Isle of Dogs Crossrail station, designed by Lord Foster. The crucial deal between Wharf and Transport for London plugs a hole in the funding of the £15.9 billion Crossrail project.

Johnson said: "Construction of the new station will get under way in early 2009. Once Crossrail arrives in Canary Wharf, it will act as the catalyst for a further economic boost - allowing the construction of more offices and other facilities including new shops and more hotels."

John Garwood of Wharf said: "This is good news. It is another step along the line for the Crossrail project, which everyone agrees is essential to London and also to the future expansion of Canary Wharf."

The City of London has also contributed £200 million to Crossrail, which will run from Maidenhead in Berkshire to Shenfield in Essex, linking Heathrow, the City and Canary Wharf.

That will put the Docklands financial centre 10 minutes from Farringdon, 17 minutes from Paddington and 44 minutes from Heathrow. Some 90,000 people work at Canary Wharf. Although jobs are going in the current financial crisis, that number is expected to grow in the long term.

Planning permission for the Isle of Dogs station was granted this month. The station is expected to be completed by 2012, and the first trains are due to run in 2017.

Crossrail is putting £350 million towards the £500 million station project, with Canary Wharf stumping up the difference. Planning permission has also been given for 100,000 square feet of shops and a leisure park above the station.

Transport Minister Lord Adonis said: "This vital new link will directly connect the heart of London's financial districts and Canary Wharf to Heathrow Airport, significantly improving existing public transport links and giving people a real choice about how they make their journeys into and across London."