The 2012 Olympic sailing venue is celebrating the signing of a £4 million deal, to build a centre the Royal Yachting Association (RYA).

It will provide accommodation and conference space in Portland, Dorset, for sailors preparing for the Games.

It is the first phase of the £30m Castle Court tourism and leisure development, which will take place on land owned by the South West Rural Development Agency next to Portland Castle. The developments would create about 600 jobs.

Work on the building will start in January and finish next autumn.

Double Olympic medallist Simon Hiscocks helped put the seal on celebrations as regeneration company Sutton Harbour Group signed the deal with the RYA and the South West RDA.

Hiscocks, silver medallist in the 49er sailing class at Sydney in 2000 and bronze medallist in Athens in 2004 said: "I think it will be a huge asset to Weymouth and Portland and play a major role supporting the sailing events up to and including the London 2012 Olympic and Paralympic Games, and thereafter."

Michael Wigley, RYA treasurer, and chairman of the Portland working party, described Portland as one of the primary training and event locations in the UK.

Nigel Godefroy, chief executive of the Sutton Harbour Group, of Plymouth, said: "This deal is a milestone in the development and underlines what can be achieved with the public and private sectors working together.

"We all want to create a year-round destination for visitors and the local community as a statement for the 2012 Games." Tony Bray, Dorset director for the South West RDA, said: "The RYA centre is the latest step in the transformation of Osprey Quay and will contribute to the diverse range of leisure and employment uses on the old Royal Naval air station site.

"We are investing about £38m to unlock Portland's potential and ensure a lasting legacy well after the 2012 Games."

The deal follows the recent announcement of a £6.6m investment by the RDA in Weymouth's seafront which will transform it in time for 2012.

Funding for the RYA project is being provided by RBS

Architects Design Group has designed the RYA building along with the rest of the Castle Court development, which was given detailed planning permission earlier this year.

The five-storey building will include reception area, meeting rooms, storage, a small shop, three floors of 24 en-suite bedrooms and a top floor clubroom, bar and dining area with views over the water.

The scheme will be built by Midas Construction.