WASHINGTON - Sarah Palin has received an extension of the deadline for disclosing her personal finances and now won't have to report until the day after her only debate with Democrat Joe Biden.

The Republican vice-presidential candidate received a four-day extension Thursday from the U.S. Federal Election Commission.

The federal financial disclosure report was initially due next Monday. Now, Palin has until Oct. 3, the day after her debate in St. Louis with Biden, the Democratic vice-presidential nominee.

Earlier this month, Biden released a decade of personal financial records that showed the veteran U.S. senator from Delaware earned less than many of his congressional colleagues.

For example, Biden and his wife, Jill, earned $319,853 in 2007. On Thursday, Biden submitted an updated report to the Federal Election Commission

Presidential, vice-presidential and congressional candidates must all file ethics reports outlining their assets and liabilities. That includes such things as sources of income, real estate held for investment purposes, stocks and debt.

Trevor Potter, general counsel for the McCain-Palin campaign, told the FEC that the campaign initially thought it had until Oct. 4 to file the report, but then learned the FEC set an earlier due date.

"Most importantly, because Gov. Palin has not previously run for federal office, it is clear to us that additional time is required to compile and prepare Gov. Palin's financial information," Potter wrote.

"As you are well aware, the Executive Branch financial disclosure form is vastly more complex than most state disclosure forms, and requires the assemblage of a quantity and level of detail far beyond that reported previously by the governor in Alaska and therefore readily available."

In granting the extension, the FEC said that if Palin requests still more time, the last possible due date would be Oct. 6.

Palin's federal financial disclosure report will provide the most complete look yet at her assets and liabilities.

For example, it will show whether she and her husband Todd hold any mortgages for real estate investments, and roughly how much any property held for investment purposes is worth.

The financial reports that Sarah Palin filed as Alaska governor list property the couple held at that point, but not how much it was worth; how much, if any, profit they made on real estate sales; or how much, if any, mortgage debt they held.

Such information is a standard part of the personal financial disclosure reports that members of Congress, administration officials and federal candidates must file each year.

The reports allow the public to see whether politicians may be receiving favourable financial treatment from people with issues before government or have any potential conflicts of interest. They also offer a glimpse of their ability to manage their personal finances.

The financial reports that Palin has filed in Alaska over the years show the Palins have often had several sources of income.

Last year, for example, Sarah Palin earned $125,000 as governor. Her husband took in $46,790 as a part-time oil production operator for BP Alaska in Prudhoe Bay, $46,265 commercial fishing for salmon from June to July in Bristol Bay, and $10,500 in Iron Dog snow machine race winnings.