The Agriculture Department should modernize its network of state and county offices, originally designed to serve Depression-era farmers and which, in some cases, now cost more to maintain than the benefits they hand out, the General Accounting Office said.

At least one of five key department agencies has a foothold in almost every one of the nation's 3,150 counties, making it "one of the federal government's largest, most decentralized field structures," the GAO said.

Investigators said they found more than 50 offices of the department's Agricultural Stabilization and Conservation Service (ASCS), where administrative costs exceeded farm program outlays in fiscal 1989.

More than 800 county offices were said to have administrative costs ranging from 10 percent to 100 percent of the farm benefits they handed out.

The report said taxpayers would save more than $90 million a year if ASCS would consolidate its high-cost offices.

No list of the high-cost offices was provided, but a coded map showed most were concentrated in the South, parts of the Northeast and in several states in the West.

Other agencies reviewed included the Soil Conservation Service, Farmers Home Administration, Extension Service and Federal Crop Insurance Corp.