A Senate committee voted yesterday to reject all proposed changes in veterans preference rights from President Carter's civil service revision bill.

Administration officials had described the changes as central to the Carter plan for improving the efficiency of the government personnel system.

After the committee's 9-to-7 vote to separate the issue of veterans preference from the issue of civil service reform, Civil Service Commission Chairman Alan K. Campbell called the outcome "indeed a disappointment."

Campbell, one of the principal proponents of change in the veterans preference law, said the Carter team "obviously does not take this as final . . . We'll continue to fight in the House and carry the issue to the floor of the Senate."

Campbell had argued that the lifetime preferences in U.S. hiring and job retention given to veterans have an unfair impact on the government's efforts to employ women and minorities.

Veterans preference requires that five points be added to the entry-level civil service examination scores of persons with prescribed periods of military service. Members of their families in some cases also benefit from the provision.

The vote on veterans preference was taken near the end of a hectic series of meetings of the Senate Governmental Affairs Committee, conducted at various times and places throughout the day. At 7:15 p.m., a roomful of senators, lobbyists and others packed into a small basement room in the Capitol saw Committee Chairman Abraham Ribicoff (D-Conn.) abandon an effort to get a final vote on the bill out of the committee last night.

In the debate on the veterans preference issue, Sen. John Glenn (D-Ohio) argued against any changes. He said that the administration would take away benefits from the very people who "served as I did at about one-third the pay of those in the private sector at the same time . . ."

"While I was orbiting, I was receiving about $16,000 a year. I had been offered two and a half times that much. I looked on (veterans benefits) as deferred pay."

Sen. Charles Percy (R-Ill) spoke in favor of the changes sought by the administration. He said "we've got to ask the veterans to look at the bigger picture. Not who can get on the payroll and sit there and know he cannot be taken off. Those are not the people we should be sitting here protecting."

The committee voted to drop the veterans preference issue from the current bill and conduct instead a joint study with the Armed Services Committee to consider the question further, and "educate the country."

A report is to be ready by the end of the year - after the November elections.

Senators made repeated mention of the political clout of the veterans lobby.

Sen. Thomas Eagleton (D-Mo.) argued in support of the president's proposed changes on the grounds that "the civil service will go rolling on like Old Man River if we delete all reference" to the proposed revision.

The president's proposals would have "refocused" veterans preferences in federal employment on Vietnam era veterans and disabled veterans, but would have curtailed preferences for able-bodied veterans long out of service, according to supporters of the changes.

The committee earlier in the day approved a compromise amendment offered by Percey on procedures for firing federal employes.

Campbell called the passage of the amendment "a real triumph" for Carter. The amendment would make it easier for managers to fire federal employes, but not quite as easily as the administration had proposed.