The number of homes for sale is tipped to fall as homeowners seek to avoid the further price slides expected to follow the financial turmoil sparked by the collapse of Lehman Brothers.

Some agents had reported that a rush of homes for sale in recent months and a fall in prices had prompted some interest from bargain-hunters. However, they fear that the latest round of credit-crunch pain will have further restricted the supply of mortgages and will have knocked confidence, despite the intervention of the US Treasury on Friday.

Miles Shipside, a director of Rightmove, the property website, said that buyers now required “bravery in the face of the ongoing turmoil in the financial markets”. Liam Bailey, of Knight Frank, the estate agent, has predicted an atmosphere of further uncertainty and no recovery before next spring.

A monthly survey of asking prices by Rightmove, released today, suggests that the average house price fell by a further £2,378, or 1 per cent, in the month to September 13. Sellers are asking an average of £227,438 for homes, £14,204 less than the peak a year ago.

The declines were less pronounced than those in August, when prices were reported to be 2.3 per cent down. However, after chaos in the City last week, Mr Shipside said: “The housing market is on its knees and will remain so until financial institutions address the disastrous state of the mortgage funding markets.”

Jeremy Leaf, of Jeremy Leaf and Co, hopes that the turmoil could help over the longer term, despite the grim outlook. He said: “Property probably became a more popular investment last week than it was the week before. Amid all the shares turmoil, investors could say: "The capital value may have gone down a bit, but it is up 100 per cent on five or six years ago.”

However, agents fear that the sudden extension of energy performance certificate laws will further strain the market. All homes for sale must be equipped with an energy performance certificate (EPC) from Wednesday of next week; previously, those that had stayed on the market since before home information packs (Hips) were launched in August 2007 were exempt.

Rightmove suggests that 98,000 Hips-exempt properties remain on the market unsold and will need an EPC from October 1, at a cost of up to £100 to the homeowner.

Mr Shipside said that it was unlikely that cash-strapped agents would underwrite the cost. He said: “This will be a real trigger-point. I foresee a lot of frank discussions, where the agent's advice will be to take the property off the market or reduce the asking price drastically.”

Nick Salmon, a director of the estate agent Harrison Murray, said: “If you are already struggling financially, another £100 will not be welcome.”

Rightmove suggests that low confidence is stunting the supply of homes coming to market, with its survey suggesting that agents have, on average, 78 for sale, against 79 in August, the first decline in seven months.

There is no escape from the new EPC rules for the growing number of homeowners, who, unable to sell, have become reluctant landlords. EPCs will also be compulsory for homes to let.

London asking prices rose by 4 per cent this month, partly restoring average values after a 5.3 per cent fall in August and the result of what Rightmove calls “summer volatility”. Mr Shipside said: “I suspect that larger and more expensive houses came on to the market in London, driven by jobs uncertainty in the City.”

House prices: the 10 best and 10 worst performing counties

Landlord's deadline

- All homes being offered for rent after October 1 must be equipped with an energy performance certificate (EPC)

- Energy performance certificates typically cost between £50 and £100

- Landlords need not have the certificate in place by that date, but must show they have taken reasonable steps to secure one

- Landlords must produce an EPC within a reasonable time - certainly before a tenancy is signed