The first is the cost of fixing London's "Walkie Talkie" skyscraper, which reflected sunlight off its concave structure at such intensity it melted parts of a car, a sum that will be "in the low single-digit millions", its chairman David Pritchard said on Friday.

Its other headache has been the fact its Qatari-backed development of Royal Dutch Shell's new British headquarters was thrown into doubt after the government decided to review plans given the green light by local officials, a move it called "disappointing".

"We are talking to everybody about the next steps," Pritchard said, adding that typical costs for such delays are between 1 and 2 million pounds.

The glass-clad Walkie Talkie, so called because of its distinctive flared shape, was blamed for warping the wing mirror, panels and badge on a Jaguar car parked on the street below the 37-storey building that is under construction.

Canary Wharf, which said it was not yet clear who would bear the costs of fixing the building, is developing the tower with Land Securities.

"The costs to date have been very minor and we are talking to specialist consultants about a long-term solution," Pritchard said on a call following Songbird's half-year results. "It will be in the low single-digit millions."

Canary Wharf Group, which controls the east London financial district of the same name, moved into other parts of London such as the south bank, where Shell's new HQ is planned, as the financial crisis took its toll on its traditional banking tenants.

The company, which also on Friday said its adjusted net assets per share rose 6.2 percent to 223 pence over the six months to June 30, reiterated its plan to become less reliant on the banking sector, where demand for new offices has dried up and rents are stagnant.

Ahead of the five-year anniversary on Sunday of the collapse of Lehman Brothers - which was one of Canary Wharf Group's largest tenants and occupied a building now used by JP Morgan - Pritchard said the company's estate would contain more apartments, shops and media and technology tenants in five years' time.

(Editing by David Holmes)

By Tom Bill

Stocks treated in this article : Songbird Estates plc, Land Securities Group plc