Mortgage interest rates plunged below 6 percent in the last week, reaching the lowest level in five months, reflecting investors’ relief over the government bailout of Fannie Mae and Freddie Mac.

Freddie Mac’s weekly survey released Thursday showed average 30-year, fixed-rate mortgages have fallen to 5.93 percent, down from 6.35 percent the week before.

The rate on 15-year, fixed-rate mortgages averaged 5.54 percent, down from 6.90 percent.

“It puts a little more buying power behind those prospective buyers in today’s marketplace,” said Greg McBride, senior financial analyst at Bankrate.com.

The new rate would slice about $76 off the monthly payment on a new $200,000 loan, compared to one month ago, Freddie Mac said.

Offsetting the good news, though, are declining home values, which would make it impossible for some homeowners to refinance their existing mortgage to take advantage of lower rates.

Looking ahead, rates may have a little bit farther to fall, says Orawin Velz, associate vice president of economic forecasting at the Mortgage Bankers Association of America.

In the fourth quarter, the organization expects rates to hit an average of 5 percent. Next year, however, she said they could pop up above 6 percent as the economy recovers.

And, lenders have told regulators that they've raised their standards for making new loans, which means it is more difficult to qualify for a mortgage.