Mortgage rates fell to the lowest level of the year this week, as rates fell on U.S. government securities. Fixed mortgage rates tend to be influenced by movements in the yield of 10-year Treasury notes.

The average rate on a 30-year fixed rate mortgage dipped to 4.84 percent this week from 4.93 percent a week earlier, Freddie Mac said Thursday. It was the lowest level since mid-December, when rates averaged 4.81 percent.

Bond yields sank after Germany's move this week to curtail certain kinds of short-selling spooked investors, who shifted money from risky European debt to safer U.S. securities. That also lowered mortgage rates.

Demand for safe investments is high on debt concerns in parts of Europe.

Freddie Mac collects mortgage rates on Monday through Wednesday of each week from lenders around the country. Rates often fluctuate significantly, even within a given day.

The average 30-year fixed rate dropped to a record low of 4.71 percent late last year, pushed down by a campaign by the Federal Reserve to reduce borrowing costs for consumers. The program ended this spring, but rates have remained low, especially after fears that Greece's government would default shook world markets.

This week, the average rate on a 15-year fixed-rate mortgage was 4.24 percent, down from 4.3 percent last week.

Rates on five-year, adjustable-rate mortgages averaged 3.91 percent, down from 3.95 percent a week earlier. Rates on one-year, adjustable-rate mortgages fell to 4 percent from 4.02 percent.

The rates do not include add-on fees known as points. One point is equal to 1 percent of the total loan amount.

The nationwide fee for loans in Freddie Mac's survey averaged 0.7 of a point for 30-year and 15-year loans, and 0.6 of a point for 5-year and 1-year loans.