Mortgage rates are once again approaching all-time lows set in January, a result of the weaker economy that may help spur a rebound in the housing market, Freddie Mac ( FRE) said on Thursday. The average 30-year fixed mortgage cost 5.03%, down from 5.15% a week ago and 6.13% a year ago. The rate for those mortgages hit a record low of 4.96% during the week ended Jan. 15. Shorter-term fixed mortgages and adjustable-rate mortgages also declined. Frank Nothaft, Freddie Mac vice president and chief economist, attributed the drop to a weaker jobs market combined with predictions of soft consumer spending and inflation. The price is far below the effective rate of 6.2% paid by consumers in the fourth quarter of 2008, making home purchases and refinancing more attractive for new homebuyers and existing homeowners alike. "Indeed, mortgage rates have drifted up and down only by about one quarter of a percent in the first months of this year," says Nothaft. "Given the recent historically low mortgage rates, homeowners have a strong incentive to try and refinance." Freddie Mac and its counterpart, Fannie Mae ( FNM), guarantee or insure more than half of the U.S. mortgage market. They have taken an even more prominent role in supporting a revival in the troubled housing market as part of the Obama administration's economic recovery plans. The government placed the two firms in conservatorship last September in the face of mounting losses that threatened their viability.