With more than 250 protesting District of Columbia employees lining the walls of the meeting hall, a City Council committee voted unanimously yesterday to postpone action one month on a new municipal personnel system independent of the federal government.

In doing so, members of the Council's government operations committee voiced determination to move ahead with the bill susbtantially in its present form, disappointing spokesman for labor unions seeking another year to redraft the measure.

After the meeting, City Council Chairman Sterling Tucker disclosed that he had asked for a postponement of the committee's approval of the bill, which had been scheduled yesterday.

Because of time-consuming consideration of the 1979 city budget and the controversial rent-color bill, Tucker said. "The whole Council has not had time to focus on this (personnel) bill . . . not only what's in it, but the implications."

Committee chairman Arrington Dixon (D-four) made the motion for the delay. One reason, he said, was that a study of the costs of the new measure had not been completed. Dixon has forecast that the city would not spend any more - and might save money - under the new bill, a claim disputed by the measure's critics.

The Council is considering the measure as Congress required in the 1975 Home Rule Charter, which calls upon the city to have its own personel system in operation by 1980.

Officials say it will take a year or more after the Council enacts the bill to draft administrative regulations to make it work. The enactment process would require a minimum of about four months.

The complex 163-page measure would create a new job-classification and salary system for all new city employees. As the result of retirements, promotions and reassignments of current employees over the next several years, it ultimately would affect all 40,000 city employees.

Because yesterday's committee session was not a public hearing, therre was no further testimony on the bill.

Union members, assembled by their leadership and supported by the AFLCIO Greater Washington Central Labor Council, marched outside the District Building before the meeting carrying protest signs. Then they went upstairs and stood quietly, listening to the proceedings, which lasted only 25 minutes.

Council member Marion Barry (D-at large), supporting a one-month delay, said he had called upon union leaders to propose specific language that might be added to the bill, and to stop general objections.

However, many union objections are seen as fundamental, Cleo Michael, president of the D.C. Council of American Federation of Government Employees (AFGE), which represents 5,000 city employees, told a reporter his group wants the right to negotiate wages - not have them determined by the city government as the measure provides.

John Colbert, a D.C. General Hospital X-ray technician, said he feared the loss of benefits.

Dixon, talking to union officials and mebers after adjournment, said the measure seeks to balance interests of employees and city taxpayers.

The unions must understand, Dixon said, that "we are not here to guarantee that all (union) suggestions are going to be accepted."

Donald M. MacIntyre, a national vice presidents of AFGE, walked away from his conversation with Dixon shaking his head. "I just think he is going to do his act four weeks from today," MacIntyre said.