WASHINGTON  The Federal Deposit Insurance Corporation indefinitely postponed a central element of the Obama administration’s bank rescue plan on Wednesday, acknowledging that it could not persuade enough banks to sell off their bad assets.

In a move that confirmed the suspicions of many analysts, the agency called off plans to start a $1 billion pilot program this month that was intended to help banks clean up their balance sheets and eventually sell off hundreds of billions of dollars worth of troubled mortgages and other loans.

Many banks have refused to sell their loans, in part because doing so would force them to mark down the value of those loans and book big losses. Even though the government was prepared to prop up prices by offering cheap financing to investors, the prices that banks were demanding have remained far higher than the prices that investors were willing to pay.

In a statement, the F.D.I.C. acknowledged that it had not been able to get banks interested in its so-called Legacy Loans Program. Scheduled to start later this month, the pilot program was aimed at selling off $1 billion in troubled home mortgages.