Wednesday's edition of The Washington Post incorrectly reported the amount of Montgomery County's 1980 capital budget. The correct figure is $51 million.

The Montgomery County Council approved yesterday a $599.4 million operating budget for 1980 that cuts the size of the county's administrative offices for the first time in 15 years and holds overall government spending to the lowest annual increase in a decade.

The final spending program allows for a possible reduction in the county's property tax rate of as much as 35 cents per $100 of assessed value - a tax relief program that would largely be funded by an unanticipated budgetary surplus of $12 million.

The council will set the tax rate in the middle of next month. At the same time, it also will determine how much of the surplus left over from the current year's budget should be set aside to offset expected revenue losses in the coming year.

If the council follows the original proposal of County Executive Charles W. Gilchrist to cut the tax rate 35 cents per $100 of assessed value, the average homeowner's tax bill would show "little if any change" because of increases in property tax assessments, according to Buget Director John Short.

But some council members indicated yesterday that they do not favor so great a tax cut in view of projected revenue losses in 1930, expected to be caused by inflation and changing statewide property assessment practices that could significantly reduce the county's assessable base.

"There is some difference of opinion over setting the tax rate (that low) because of an acute shortage we anticipate next year," said Councilman Mike Gudis. "I don't want to give the impression that what is proposed by the executive is carved in granite."

Gilchrist, nevertheless, praised the council for honoring "its commitment to the taxpayers to exercise fiscal constraint." Any executive veto is unlikely, a Gilchrist spokesman said.

The council's decision to pass a bugget that is only $700,000 more than Gilchrist's original recommendation met with mixed reaction.

"It's not as good as I'd like but better than it could have been," said Councilwoman Rose Crenca, a memeber of the Taxpayers League, which tried unsuccessfully to win voter approval of a tax-cutting charter referendum last November.

Councilwoman Elizabeth Scull contended, however, that although a "Propostition 13 mode is sweeping the land. . . we cannot ask our citizens to settle for paying for inflation by giving up services."

Under Gilchrist's proposal, the overall tax rate would drop from $3.59 to $3.24 per $100 of assessed value, but it would vary slightly depending on the region of the county.

Gilchrist was able to propose a tax cut without significantly slashing government programs. But he did recommend reductions in the county's central government work force, prompting the first cut in those administrative jobs since 1965.

The council cut 35 vacant positions from the central government work force complement of 5,313. It also provided 6.52 percent salary increases for these workers. In addition, school employes and the Park and Planning Commission staff will receive 5 percent pay raises, while employes at Montgomery College will have 7 percent salary increases next year.

In one of their most substantial reductions, the executive and council refused to appropriate $1.73 million for 65 new teachers and related instructional costs for the public schools. The school board had sought the new positions to reduce class size.

The council's $281.56 million operating buget for the school system is $2.84 million below the school board's request and about the same as the executive's. The council and executive also projected 757 student below school board estimates and cut $500,000 for teachers salaries, textbooks and furniture to relfect that loss. But they restored six social worker positions that the conservative majority of the Board of Education wanted to eliminate.

In addition to the operating budget, the council added about $100 billion in new expenditures for the county's capital construction program that exceeds $1 billion in outlays over the next six years.

In so doing, they followed Gilchrist's recommendation to provide $9 million to replace buses for the popular Ride-On system that recently cut back about a quarter of its service because of persistent maintenance problems.

The council also authorized the purchase of 40 new buses for extended Ride-On service in the 1980s when the new county office building in Rockville and the Metro station in Bethesda open.

In a few significant areas, the council departed from Gilchrist's recommendations. They declined to close the Four Corners Library in Silver Spring, and they cut $159,700 from the police department budget, which, among other things, will mean a possible reduction of seven positions in the new 40-member police recruit class.

In approving a $26.4 million budget for Montgomery College, the council agreed with the college board of trustees that tuition should increase between $2 and $4 per semester hour next year. However, they also recommended a study of possible joint use of the new Germantown campus as a community college and junior high school.