All-time highs for housing affordability persisted this week as interest rates for fixed-rate mortgages hovered near their record-breaking lows, a sign that Europe continues to ward off investors.

Real estate Web site Zillow found only a minor shift for the 30-year fixed-rate mortgage, which lingered between 3.70 percent and 3.75 percent before nestling at 3.69 percent Tuesday.

The 15-year loan stayed near 2.95 percent, along with rates for 5-year and 1-year adjustable-rate mortgages (ARMs) that averaged 2.65 percent, according to the Web site.

“Mortgage rates rose late last week as positive U.S. economic news offset ongoing concerns about Europe’s economic situation,” Erin Lantz, director of Zillow Mortgage Marketplace, said in a statement.

She said rates climbed back down to historic lows as concerns about Spain’s deficit “renewed doubt about the long-term feasibility of the [European Union’s] fiscal pact.”

The fate of Europe remains of chief concern to wary investors, who continue to leave for safe-haven U.S. Treasury debt overseas.

Lenders benchmark interest rates for mortgage products against Treasury yields, which expand or contract as investors finance government debt.

This week Greece will reportedly ask investors to accept write-downs by more than 50 percent, a debt swap that government officials hope will secure at least 75 percent in participation, according to Bloomberg News.

The news service said that the debt swap would meet a critical requirement of the second bailout cleared by euro zone finance ministers last week.

Lantz added that Zillow expects rates to fluctuate unless markets react sharply to news from Greece this week.