Hundreds of investors are set to make massive profits after they backed Birmingham's Brindleyplace development.

The lucky speculators have seen their initial shares double since they joined a Limited Partnership scheme set up by Brindleyplace in 2003.

The scheme, which involves 391 private investors paying into a 49.9 per cent share in the city centre development, was hailed as one of the most profitable by a leading property consultant yesterday.

The director of Argent, the company which manages the office, residential and leisure destination, said those who backed the scheme "have had a fantastic ride".

The latest financial figures show that the #99 million equity invested in October 2003 is now worth just over #200 million. Investors also receive nine per cent of their initial outlay each year as part of the package.

The release of the figures comes during a buoyant time for Birmingham's commercial property sector.

Another prestigious city centre development - The Mailbox - has just announced that one of its flats has broken the #400 per square foot barrier.

And council chiefs have promised that uncertainty surrounding a two-acre plot off Great Charles Street will end next month when one of the "biggest corporate land deals that Birmingham has seen" is signed.

The lucrative Brindley-place scheme has been bolstered by the stability of the site, which has seen a number of blue chip firms such as Deloitte's, BT and RBS sign long-term leases.

Gary Taylor, director of Argent, said: "The investors have had a fantastic ride."

Jim Prower, finance manager at Argent, aired a note of caution as investors are not allowed to recoup their profits until 2009, or sooner if the development is sold.

Brindleyplace's emergence as an investment hotspot has been assisted in recent years by the development of Birmingham's commercial property sector.

The selling agents for The Cube, the mixed use final phase of The Mailbox, announced yesterday the highest price per square foot for an apartment scheme in Birmingham.

The apartments, aimed towards buy to let purchasers, will be sold for #446 sq ft.

Knight Frank announced the figures as they prepared to sell the last 24 units in The Cube West.

David Fenton, head of residential development for Knight Frank's Birmingham office, said: "Other UK cities have had schemes which have broken the #400 per square foot barrier, but for Birmingham this is a recent phenomenon."

Coun Ken Hardeman (Con Brandwood), Birmingham City Council's Cabinet member for regeneration, announced more good news for the city's property market.

The regeneration chief said at least three developers are still in talks with the local authority over a two acre site in the Jewellery Quarter.

HBG Properties, part of a #5 billion Dutch conglomerate, decided against a #23 million investment in the land, off Great Charles Street, shortly before contracts with the council were due to be signed earlier this month.