Mortgage rates are again dropping to near-record lows -- below 5 percent--in the wake of the Federal Reserve's decision to buy up Treasury bonds and mortgage securities.

Lower rates may help spur home sales, but analysts expect much of the action to come from homeowners looking to refinance.

And some are bound to be disappointed, mortgage experts cautioned Thursday. The problems that created the mortgage meltdown mess mean tighter rules and regulations for home buyers and those seeking to refinance. And tight lending standards make it much harder for all but the most creditworthy borrowers to qualify.

"A lot of people could not requalify for the loan they have now," said Alex Stenback with Residential Mortgage Group in Minnetonka. "There are tougher credit standards. You do have to have a certain amount of equity in the property. You do have to meet the now-tighter debt-to-income ratio requirements."

Keith Gumbinger of HSH Associates, a publisher of mortgage information, said good interest rates were available to all kinds of borrowers in all kinds of credit circumstances when the market was running flat out five years ago. That's not the case today.

"You must be a much better borrower than you had to be before," he said. "For some borrowers, you have to get used to hearing 'no.'"

By snapping up Treasury securities, the Fed boosts their prices, and that drives down the yield, or interest rate. The 10-year Treasury bond dropped Wednesday by the biggest one-day amount since 1981. It rebounded slightly Thursday.

Analysts expected mortgage rates to follow suit, and they did come down Wednesday and Thursday.

The national average rate on a 30-year, fixed-rate mortgage fell to 4.94 percent, down nearly a quarter of a percentage point from a day earlier, according to HSH Associates.

Stenback said Thursday afternoon that rates on a 30-year fixed rate mortgage were 4.5 to 4.625 for a best-case scenario borrower.

Will they stay that low? Probably not.

"When we see these really dramatic drops, there's a little bit of a snap-back effect," said Stenback. "But it probably won't go back up to where they were before."

Paul Schuster, vice president of Marketplace Home Mortgage and head of the Minnesota Mortgage Association, called the downward trend positive but said it won't solve the housing problem alone. "It's a key to affordability, and low rates are critical to helping the housing market recover, and it was a commitment by the Federal Reserve to support that in a big way."

Home buyers and owners who want to refinance should be prepared for a longer process, Schuster said, and for different rates or costs, depending on their credit scores and loan-to-value ratios. "Now, there might three or four different levels" for transactions that previously would have been priced equally, he said.

Stenback said he expected a "huge" number of people to try to refinance but urged patience as the underwriters, closers and others scramble to keep up with demand.

"They cut staffs, and now we get this giant glut of new refinancing business," he said.

Suzanne Ziegler • 612-673-1707