Hybrid adjustable-rate mortgages remain the most popular and most common ARM product, according to a survey by Freddie Mac.

Freddie said initial rates are at the lowest levels recorded in the 28-year history of its ARM pricing survey, reflecting, in part, the low levels of the Treasury yields that are used as indexes.

The 5/1 hybrid ARM continued to be the most popular loan product offered by lenders offering adjustable-rate mortgages.

Nearly all ARM lenders participating in the survey offered such a loan. The next most popular products were the 3/1 and the 7/1 hybrids. Less than one-half of lenders offered the 1-year adjustable, and only 4% offered a 3/3 ARM, which adjusts once every three years.

In early January, the interest-rate savings for the popular 5/1 hybrid ARM compared to the 30-year fixed-rate mortgage amounted to about 1 percentage point, about the same as during January 2011.

The initial interest rate differed little for the 1/1, 3/1 and 5/1 products, according to the survey’s results.

Longer-term hybrid products were also available, Freddie said, with 63% of lenders offering a 7/1 and 38% offering a 10/1. Because of the long initial fixed-rate period of these loans, the initial interest rates were priced closer to the rate on a 30-year FRM for these products.

Among 121 ARM lenders surveyed, 65% offered loans tied to constant-maturity Treasurys, down from 71% in 2011; the remaining offered products tied to future rates indexed to the overnight London Interbank Offered Rate.

The eurozone crisis and the uncertainty over LIBOR movements may have led some current borrowers to avoid LIBOR ARMs, Freddie said.

The survey was conducted from Jan. 3 to Jan. 5. (Click on chart to expand.)

Write to Kerry Curry.

Follow her on Twitter @communicatorKLC.