Fixed-rate mortgages eased slightly over the past week — remaining near historic lows — while adjustable-rate mortgages hit a new nadir, Freddie Mac reported Oct. 27 in its Weekly Primary Mortgage Market Survey.

The 30-year fixed-rate mortgage inched down 0.02 percentage points from the previous week to 3.98 percent (down from 4.4 percent a year ago). The 15-year fixed-rate slipped 0.01 percentage points to 3.3 percent (down from 3.77 percent a year ago).

Meanwhile, five-year Treasury-indexed adjustable-rate mortgages fell 0.06 percentage points to 2.91 percent (down from 3.45 percent a year ago) and one-year rates dropped 0.19 percentage points to 2.79 percent (down from 3.23 percent a year ago).

"Mortgage rates eased slightly this week with fixed-rate loans hovering above all-time lows and ARMs reaching a new nadir,” Freddie Mac Chief Economist Frank Nothaft said in an accompanying news release. “The high-degree of home-buyer affordability in recent months translated into a 1.4 percent pickup in existing home sales during October, according to the National Association of Realtors.”

View Freddie Mac’s Weekly Primary Mortgage Market Survey, including regional breakdowns: http://freddiemac.mediaroom.com/index.php?s=12329&item=89645 .