The Fairfax County Board of Supervisors yesterday sold $35 million in bonds at what county officials described as "a substantial low interest rate will realize a savings of $3.05 mil-bond ratings for the county.

Walter Crailie Sr., the county's bond consultant, said the low interest rate will realize a savings of $3.05 million for county taxpayers over the 20-year life of the bonds.

Fairfax sold the $35 million worth of general obligations bonds at a net interest rate of 5.2698 percent, which is below the current long-term interest rate of 6.1 percent.

The county received four bids for its bonds. The winning bid was submitted by a New York consortium headed by Citibank of North America; Nerril-Lynch; White, Weld, Capital Markets Group; and First Boston Corp.

The bond sale will provide $19.05 million for school construction and improvements, $11.45 million for a new courthouse and $4.5 million for parks.

Earlier this month, Standard and Poor's Corp., one of two companies that rates municipal bond issues, upgraded its rating of the county's bonds from a double-A-plus to triple-A.

Moody's Investor Service, the other company that rates municipal bond issues, continued its triple-A rating for the county's bonds.

Fairfax County is one of only six counties nationwide - including Montgomery County - to be given triple-A ratings by both companies, county officials said.