White-collar salaries in the private sector rose by 3 percent to 6 percent between March 1984 and March of this year, according to newly released data the government uses to compare its salaries with the going rate for similar jobs in industry.

But even that modest jump in private-sector pay -- about half the average annual pay raise rate during high inflation periods of the 1970s -- will be more than civil servants can expect to get. Chances are they will have to wait until sometime in 1987 for their next general increase.

By law, federal workers are supposed to get catch-up-with-industry pay raises each Oct. 1. But presidents Nixon, Ford, Carter and Reagan all either lowered the recommendations of their pay agents or delayed the effective date of the respective raises until January, and in some cases did both.

Last year, for example, the president's pay agents said that according to the data collected by the Bureau of Labor Statistics, federal workers were due an average increase of 18.2 percent. But the agents -- the secretary of Labor and the directors of the Office of Management and Budget and the Office of Personnel Management -- said the pay survey is incomplete because it didn't measure a wide range of occupations, or take into account the value of fringe benefits or wages paid the 12 million state and local government employes.

Instead of the 18.2 percent recommended for October, the president proposed and Congress approved a 3 1/2 percent raise effective last January. In 1983, U.S. workers got a 4 percent raise in January.

The current average salary for white-collar (professional, technical, clerical and administrative) workers here is $31,187. According to the OPM, the median salary for the area's 300,000 white-collar workers is $27,252.

Sometime late next month the pay agents will again recommend a catch-up-with-industry raise that the president will almost certainly reject. His budget submitted in January proposed that feds take a 5 percent pay cut in January, and the budgets now being worked on by Senate-House conferees both call for a federal pay freeze next year.

The Reagan administration is expected to propose expanding the BLS survey to include more small private-sector firms, and also to measure the value of civil service versus industry fringe benefits. The recommendation may also include surveying salaries of state and local government workers.

BLS data notwithstanding, federal workers are looking at the prospect of no pay raise next year even though the government says that private industry wages for similar jobs are on average up by 2.3 percent for photographers to as much as 6.2 percent for chief accountants.