Freddie Mac released its weekly update on national mortgage rates on Thursday morning, showing renewed slippage in mortgage rates after last week's brief movement upwards.

30-year fixed-rate mortgages (FRMs) ticked down two basis points to 4.13%. 15-year FRMs fell one single b.p., slipping to 3.23%. One year ago, 30-year FRMs cost 4.37%, and 15-years 3.41%.

5/1 adjustable-rate mortgages (ARMs) dropped two basis points to 2.97%. 1-year ARMs slipped one b.p. to land at 2.39%. A year ago, 5/1 ARMs were at 3.17%, and 1-year ARMs at 2.66%.

Freddie Mac Vice President and Chief Economist Frank Nothaft noted that there was little news on the economy this past week, capable of shifting mortgage rates more drastically. Industrial production rose slightly in June, but was still below "market consensus forecast."

Elsewhere in the markets, the housing sector as a whole is showing continued weakness. The SPDR S&P Homebuilders ETF (XHB -0.54%), which tracks the value of publicly traded homebuilders, has declined 3.4% in value over the past seven days, slipping below $31 a share in midday trading Thursday. This followed a 2.1% decline in the preceding week.