The Prince William County Board of Supervisors has decided once more to seek voter approval to finance construction of a new courthouse.

On March 31, voters will be asked to consider a bond referendum that would pay for a new court complex. County judges and other court officials have been complaining since 1957 that court facilities, which are scattered in several buildings including one condemned structure, are inadequate and should be replaced with larger, more modern ones.

The March 31 referendum will be a drastically slimmed-down version of one that was overwhelmingly defeated in 1978.

The new referendum asks for bond spending of $6,925,000. The 1978 referendum was for $18 million and would have financed a new courthouse as well as a new jail and government center.

The supervisors, in their unanimous vote last week, decided to scrap controversial plans to build a new courthouse in Independence Hill or on other sites closer to the more populous eastern part of the county. The new courthouse would be built in Manassas, the historic county seat in western Prince William County, a short distance from the 19th-century courthouse on Lee Street.

The supervisors acted under an implied threat from Chief Circuit Court Judge Percy Thornton to order them to build the courthouse with county operating funds, as was done recently in Loudoun County after voters twice defeated referenda.

"That would have a dreadful impact on the tax rate," said board chairman Kathleen K. Seefeldt. "We would have had to incease our tax rate by 23 cents for one year."

Under bond financing, the present tax rate of $1.40 would be raised an average of 2.3 cents a year for the first five years -- a "minimal increase," according to Seefeldt.

The new courthouse would cost $9.5 million. Manassas would contribute $1.9 million and Manassas Park, $350,000. The remaining $325,000 not covered by the bond referendum represents the cost of the land, which is already owned by the county.