An Office of Personnel Management study charges that "overgrading of federal jobs continues to cost taxpayers $700 million a year and that agencies aren't doing enough about it.

OPM found two years ago that agencies were paying employes for duties not actually performed, adding duties to inflate grades and assigning new titles to old functions to boost pay. An estimated 14 percent of the work force was said to be overgraded.

The new critical study of agency personnel actions, the third on overgrading made by OPM since 1978, will be the subject of a meeting with personnel officials Tuesday.

OPM said in 1978 and 1983 that the upgrading problem was particularly serious in the Washington area, where it maintained that nearly one of every three civil servants is overpaid. The average white-collar civil servant in the Washington area earns about $31,000 a year.

Outside of Washington, OPM said, about 8 percent of all white-collar jobs are overgraded.

OPM's recent follow-up study says that most agencies have failed to find any significant overgrading problem, and have reported instead that many more jobs than they thought are undergraded.

Rep. Patricia Schroeder (D-Colo.) said agency classification studies "lend credence to the view that OPM's 1983 job classification study was 'fixed' to support the view that U.S. workers are overpaid."

Schroeder chairs the House Civil Service subcommittee and represents Denver, a major federal employe job center.

She said the government should pay higher salaries to scientists, engineers and computer experts and take care of the job classification system which she said has "artificially downgraded" jobs dominated by women by not recognizing their worth.

OPM's two earlier job classification studies -- one under Reagan and one during the Carter administration -- also found some undergrading of jobs, but said most of the classification errors had resulted in higher ratings and pay than were proper.

Agencies were told then to review jobs to see if they are graded properly. And last year OPM sent out teams to 116 federal installations to see how agencies were handling position classification.

In most cases, agency personnel officials told OPM that their biggest classification problem was job undergrading.

In addition, agencies told OPM in the recent study:

*They had found only about a fifth of the overgrading errors noted by OPM.

*They found 50 percent more jobs were undergraded, and therefore underpaid, than OPM did in its 1978 and 1983 studies.

*Reclassifications had led to promotions and pay raises for 95 percent of the jobs found to be undergraded. Only 64 percent of the jobs identified as being overgraded have actually been taken care of.

OPM's report says that Defense Department agencies have a "somewhat" better record than other agencies of taking care of overgraded jobs.

A spokesman for OPM said the problem is that agencies appear to have concentrated their classification efforts on jobs where employes and bosses complained.

"Most complaints, naturally, deal with undergrading" because people aren't as likely to complain when a job is overgraded, the spokesman said.