PLANS for a flagship new marina in Portland Harbour have been unveiled.

Invitations have gone out to marine developers across the country to build a 600-berth development at Osprey Quay.

Scheme backers at the South West Regional Development Agency say the marina would be one of the south coast's biggest operations, offering unparalleled access to the open sea and shore-side hotels, restaurants and shops.

Commercial property consultants handling the project said they hope to appoint a contractor during the summer and that several developers had already expressed an interest.

Head of operations for SWRDA Dorset Kay Homer said that 2004 promised to be a pivotal year for Osprey Quay.

She said: "This year we will begin to see some significant changes as the results of a lot of hard work by ourselves and our many partners become a reality.

"A new marina would bring new jobs and new visitors to the area and provide a welcome boost to the tourism sector.

"The size and scale of the scheme that takes into account many diverse projects and rewarding partnerships, will contribute to a landmark opportunity that will provide a significant and long-term economic boost, not just to Portland but to Dorset and the South West."

SWRDA has promised the new facility will be closely linked to the operations of the new £7.85 million Weymouth and Portland Sailing Academy.

The academy is in line to host the Olympic sailing events if London's 2012 bid is successful.

Academy chairman Bill Ludlow said he had been given assurances that they would be consulted during the construction.

"Facilities would be created that are needed by both the academy and the marina. We are broadly supportive."

The new marina would nearly double the number of walk-on berths available in Weymouth and Portland.

The Weymouth and Portland Borough Council-run inner harbour currently has 430 pontoon moorings, while the privately-owned marina offers 271 berths.

Weymouth Marina operators Dean and Reddyhoff, who said it has around 60 or 70 people waiting for berths, declined to comment on the new proposals.

Marina manager Russ Levitt said: "Demand for berths has definitely gone up - the resort has become a lot more popular over the years."

Britain's biggest marina operator is currently Marina Developments Ltd, based at Southampton.

The company's marina director, John Eads, said they had been approached about the plans.

Boat-owner representatives in the borough gave the news a cautious welcome.

Terry Phillips, the chairman of Weymouth Harbour Cruising Association, said: "It is most probably a goer as long as it is priced right."

Weymouth and Portland Cruising Association's moorings officer, John Birtwistle, said the new marina would not affect a lot of his members as they were not in the market for commercial berths.

Consent from the planning and harbour authorities will be needed before building starts.

Portland Port director Rupert Best said: "In principle the port has no objection to a marina in the harbour, but we will need to balance the needs of a variety of users in considering the plan."

The proposed marina would be one of the first developments at Osprey Quay, which is set to benefit from more than £10 million of investment from SWRDA over the next few years.