The FHA insures lenders against default on low-downpayment mortgages made to borrowers whose credit profiles don't quite measure up to the standards set down by Fannie and Freddie, the two secondary market institutions created by Congress to bring liquidity to the housing finance sector.

Perhaps would-be borrowers have been late on their credit card payments on too many occasions over the last year or two. Maybe they have too much credit, or perhaps the don't earn enough to qualify for the conventional mortgages that Fannie and Freddie are willing to buy from local lenders.

Whatever the reason, lenders consider FHA loans to be somewhat more risky, a fact borne out by the most recent delinquency statistics published by the Mortgage Bankers Association.

In the third quarter, the MBA said, 12.2 percent of all FHA borrowers were at least one month behind on their payments while just 2.3 percent of all conventional borrowers were late.

Also, while the year-over-year foreclosure rate declined for conventional loans in the third quarter, it was up for FHA loans.

Because of the greater risk, lenders charge slightly more for FHA-insured loans than conventional low-downpayment mortgages backed by private insurers. According to HSH Associates, a Pompton Plains, N.J., financial publisher, the current difference is about 0.10 percentage points.

However, fees on FHA loans also are somewhat higher, including insurance premiums, which must be paid up front at closing rather than on a monthly basis, as private insurers allow.

The new FHA limits cover not only the government's basic 203(b) one-to-four family loan program but also several other key initiatives, including mortgages for disaster victims, rehabilitation loans, loans on properties in declining areas, condominium mortgages and home equity conversion mortgages.

Loan limits for two-family properties now range from $220,992 to $400,548. On three-unit buildings, the ceiling ranges from $267,120 to $484,155, and on four-unit properties, the maximum runs from $331,968 to $601,692.