U.S. fixed mortgage rates continued to move up this week for the fourth consecutive week, hitting the highest level in a year, according to the Primary Mortgage Market Survey released by Freddie Mac on Thursday. The U.S. mortgage giant said the 30-year fixed-rate mortgage (FRM) rose to 3.81 percent in the week ending May 30, up from 3.59 percent in the previous week. It has trended up nearly half a percentage point since the beginning of May. The 15-year FRM, a popular choice for those looking to refinance, rose to 2.98 percent this week from 2.77 percent in the previous week. Fixed mortgage rates became higher following a growing market sentiment that the Federal Reserve may lessen its accommodative policy stance, said Freddie Mac Vice President and Chief Economist Frank Nothaft. But he also noted that mortgage rates remained low historically, helping to keep home-buyer affordability high, which should continue to aid home sales and construction as the housing market continued to recover. In addition, the five-year Treasury-indexed hybrid adjustable-rate mortgage (ARM) edged up to 2.66 percent, while the one-year Treasury-indexed ARM stayed at 2.54 percent.