Plans for the second and final phase of a £25 million redevelopment scheme in Birmingham's core business area have been passed by the city's planners.

Nurton Developments completed the first phase of the landmark Priory & Cannon House office block last year, when Cannon House was relaunched after an extensive refurbishment of the building.

Now the developer will move ahead with its proposals to transform Priory House in an even more dynamic fashion.

The design for the property includes a futuristic glazed entrance projecting from the new facade, 40,000 sq ft penthouse office space, plus basement parking incorporating improved disabled parking facilities.

The planning application has been approved by Birmingham City Council's planning committee. Work is expected to

start on site within four to six weeks and be completed before Christmas 2008. The main contractor is Ashford Construction, who oversaw the refurbishment of Cannon House.

Architect Stuart Taylor, of Seymour Harris Architecture, said the plans had been approved within the statutory time period, and without modification.

"We have worked very hard with the planning department, to ensure the smooth passage of what is a complex application, through extensive consultation and discussion," he added.

Priory House sits on the western edge of the Steelhouse Lane Conservation Area.

Nurton's scheme was praised by Coun Peter Douglas Osborn, chairman of the Conservation and Heritage Panel, who welcomed the idea of bringing the existing building back into use, and said the proposed development would be "an asset" to the Steelhouse Lane Conservation Area.

Stuart Taylor said: "Coun Osborn and the panel had already seen the plans, and discussed them, in June, and there had been very positive feedback relating to the redevelopment and re-use of the building, revitalising existing stock, which Nurton is renowned for.

"The area is undergoing a renaissance in terms of prime location and regeneration and this is a major contribution towards it."

Nurton is keen to accentuate Priory's prominent position - on the corner of Colmore Square and Priory Queensway - to best effect while, at the same time, complementing its sister property, Cannon House, next door.

However, while there will be a degree of continuity between the two buildings. Priory, due to its faceted facade compared to Cannon's curved outline, will have a distinctive identity of its own, with a stunning glass centrepiece projecting from the building.

"The fact that the council approved the application, which included contemporary forms and materials, within an historic conservation area, emphasises the quality of our design proposals, and also s hows that the city council is forward-thinking in its strategy for the redevelopment of the city centre," said Stuart Taylor.

Guy Bowden, director at Nurton Developments, said: "I'm really looking forward to this scheme starting, because its striking design will bring further prominence and identity to the area as a whole."

The remaining facades will be renovated, using the same, specialist subcontractors who helped transform Cannon House . A further 20,000 sq ft of rooftop space will be constructed, to link up with the existing 20,000 sq ft that already runs across the top of both buildings at the rear, which will be combined and offered as top-of-the-range, penthouse office suite on the new seventh floor.

Nurton is also investing additional sums to adhere to strict, thermal and environmental criteria, in order to achieve a BREEAM excellent rating for both buildings.

Letting agents are GSD and GVA Grimley.