Mortgage rates continued a gradual climb this week for the fourth consecutive week, with rates on 30-year fixed-rate mortgages approaching highs for the year registered in February, Freddie Mac said in releasing the results of its latest Primary Mortgage Market Survey.

For the week ending April 14, rates on 30-year fixed-rate mortgage averaged 4.91 percent with an average 0.6 point, up from 4.87 percent last week and 5.07 percent a year ago.

The 30-year fixed-rate mortgage hit an all-time low in Freddie Mac records dating to 1971 of 4.17 percent during the week ending Nov. 11. This year, rates on 30-year fixed-rate loans have ranged from 4.71 percent in early January to a high for the year of 5.05 percent during the week ending Feb. 10.

“Although rates on 30-year fixed mortgages have risen four weeks in a row, they have remained below 5 percent for eight straight weeks now, helping to maintain affordability in the housing market,” Freddie Mac Chief Economist Frank Nothaft said in a statement.

Rates on 15-year fixed-rate mortgages averaged 4.13 percent with an average 0.7 point, up from 4.1 percent last week but down from 4.4 percent a year ago. The 15-year fixed-rate mortgage hit a low in records dating back to 1991 of 3.57 percent in November.

For 5-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) loans, rates averaged 3.78 percent with an average 0.6 point, up from 3.72 percent last week but down from 4.08 percent a year ago.

The 1-year Treasury-indexed ARM averaged 3.25 percent with an average 0.6 point, up from 3.22 percent last week but down from 4.13 percent a year ago.

Looking back a week, the Mortgage Bankers Association said demand for purchase loans was down a seasonally adjusted 4.7 percent during the week ending April 8 when compared to the week before, and down 11.4 percent from a year ago.

Requests for refinancings accounted for 60.3 percent of total mortgage applications, the lowest refinance share since May 7, 2010, the MBA said in its Weekly Mortgage Applications Survey.

In a March 15 forecast, MBA economists said they expect rates on 30-year fixed-rate loans will average 5 percent during the first half of this year, rising to an average of 5.3 percent in the third quarter and 5.5 percent in the final three months of 2011.