Some of the world's landmark buildings could come on to the market in a rare opportunity thrown up by American International Group's forced asset sale.

AIG chief Edward Liddy says that the final "for sale" list will be ready in a week. It is expected to include some of the $16 billion (£8.6 billion) it holds in global property.

AIG has more than 53 million sq ft of commercial property around the world, including its award-winning headquarters in Fenchurch Street and its AIG global headquarters at 70 Pine Street in lower Manhattan — an historic 66-storey building finished in 1932.

It also still owns the building it started in on the Bund in Shanghai.

"Many of AIG's properties could be trophy properties that don't come up for sale very often," said Ray Torto, global chief economist for CB Richard Ellis Group.

But a property sell-off could not come at a worse time for AIG. US commercial property prices fell 9.7% in July with Lower Manhattan prices down to about $442 a sq ft, more than $504 a sq ft last year.

Liddy said his priority was to repay the $85 billion in emergency loans from the US Federal Reserve as quickly as possible. To do that, AIG would need to sell off a range of assets that is likely to include a stake in London City Airport.

"We're going to take those assets which are probably very valuable, but can also be digested by buyers in relatively manageable bites, and we will simply start to market them," he said.

"I hope within the next seven to 10 days to be out there with a plan that lists everything that's for sale and maybe even execute some of those transactions by then," said Liddy, a former chief of insurer Allstate Corp appointed as part of the Fed deal.

If the loan is not repaid, the government can take almost 80% stake of the company.

Analysts believe AIG's aircraft leas­ing unit, International Lease Finance Corp, and its large US life insurance and annuity arm, American General, could be high on the "for sale" list.

Liddy said that after the sales, AIG would focus on its traditional strengths in property-casualty insurance.

"It will look a lot like it did prior to 1998, with less reliance on the financial services side," said Liddy.

Liddy said a last-minute attempt by a group of large AIG shareholders, possibly including former chief Hank Greenberg, to avoid the sell-off, was unlikely to work out.