A multi-million pound deal engineered by agents Knight Frank has helped to clinch the sale of the first 75 apartments at The Cube - the final phase of The Mailbox in Birmingham.

The significant deal between the Birmingham Development Company (BDC) - developers of The Mailbox - and property investment specialists Claremont Group, saw more than £13 million worth of apartments sold in a land-mark agreement completed just days before the scheme is launched to the public.

Mark Evans, partner at Knight Frank, said: "This deal demonstrates the colossal demand for city living at this iconic building.

"Without doubt, The Cube is one of a kind. There will never be another building like it in Birmingham, if not the UK, and clearly those in the market to buy a city apartment have realised this.

"We have already had over 800 inquiries for The Cube and so we are expecting the announcement of this deal to trigger even greater demand for the remaining apartments."

Edgbaston-based property investment firm Claremont Group released the apartments in three phases to their clients with the properties selling within three weeks.

Perm Saini, a joint director at the firm, said: "The Cube is one of Birmingham's most anticipated developments. We were delighted to be given the opportunity to offer 75 of the apartments to our investor client base ahead of the public launch.

"The speed with which the apartments sold reflects the faith our investors have in this development.

"The apartments are expected to command premium values on resale and provide superb rental prospects."

Prices are expected to start from £100,000 for the remaining one and two bedroom apartments stretching to £850,000 for spectacular duplex apartments.

There are nine floors of residential apartments at The Cube, but Knight Frank and BDC have split each floor plate into two with one side designated to investors and the other to owner occupiers.

Alan Chatham, director of BDC, said: "We have deliberately chosen to change the sales programme from the traditional formula used by the modern house builder and have instead opted to divide each floor in half, one side to serve investors, the other aimed at owner occupiers.

"The Cube is an exciting product and the stampede to buy the first release under-lines investor faith.

"Investors have bought into the concept, the high quality specification and the location of the development, and are clearly confident of capital returns."

The Claremont deal means five floors of the investor-aimed apartments are now tied up. A further four floors of investor aimed apartments remain, to be sold through Knight Frank.

The Cube is the final phase of The Mailbox development in Birmingham and will comprise 244 apartments, a boutique hotel, rooftop restaurant, designer stores and state-ofthe-art offices.

The £100 million scheme by BDC has been designed by Ken Shuttleworth, the architect behind London's award-winning Gherkin. Demolition and enabling works are scheduled to begin this month and first completions are scheduled for 2008.