U.S. 30-year fixed-rate mortgages declined slightly to 3.98 percent in the week ending April 5 as recent economic indicators were mixed, mortgage finance giant Freddie Mac said Thursday.

The 30-year rate was down from 3.99 percent in the previous week and far below the previous year's rate of 4.87 percent.

Average weekly mortgage rates were little changed this week amid mixed signals on the health of the economy, said Frank Nothaft.

The estimate of U.S. GDP growth in the fourth quarter was unchanged at 3 percent, the strongest pace since the second quarter of 2010. But the Federal Reserve's March 13 policy meeting said the housing market was still depressed. It supported the continutation of the maturity extension program through June 2012, but didn't announce any addition stimulus, said Nothaft.

Most of March's housing numbers disappointed, but a report from Wells Fargo said that the spring season is expected to be strong.

The 15-year fixed-rate mortgage fell to 3.21 percent from 3.23 percent in the previous week and was below 4.10 percent in the prior year.

Five-year Treasury-indexed hybrid adjustable-rate mortgages (ARMs) averaged 2.86 percent, down from 2.90 percent in the last week and 3.72 percent in the prior year.

One year Treasury ARMs averaged 2.78 percent, unchanged from the prior week and below 3.22 percent in the same period of last year.