WASHINGTON, May 30 (Xinhua) -- Mortgage rates dropped in the United States, the U.S. Federal Home Loan Mortgage Corporation, commonly known as Freddie Mac, said on Thursday.

For the week ending May 30, 30-year fixed-rate mortgage (FRM) in the United States dropped to 3.99 percent from the previous week's 4.06 percent. In the same period one year ago, the 30-year FRM averaged 4.56 percent.

Besides, Freddie Mac noted that 15-year FRM this week dropped to 3.46 percent, which was lower than previous week's reading of 3.51 percent.

"Lower rates should, however, give a boost to the housing market, which has been on the upswing with both existing and new home sales picking up recently," said Khater.

Mortgage Bankers Association reported on Wednesday that mortgage applications in the United States dropped last week, even as mortgage rates were lower than the same period a year ago. The drop in mortgage applications came despite lower mortgage rates, which should have led to an increase in application volume.

Freddie Mac is a corporation founded by U.S. Congress with an aim to promote the stability and affordability in the U.S. housing market by purchasing mortgages from banks and other loan makers. The corporation has been conducting weekly surveys on U.S. mortgage rate since April 1971.