President Carter's Pay Advisory Committee yesterday endorsed the administration's current practice of exempting low-wage workers from the White House wage guidelines, but put off any decision on where to set the cutoff level.

In the face of an obvious disagreement between labor representatives on the panel and management members, the commitee voted to approve the procedure in principle and ask its staff to work out details in private.

Nevertheless, the action yesterday effectively cleared away the last of the secondary items on the panel's agenda, leaving the next session open for consideration of the key question of what to recommend for a basic wage guideline.

Although the committee legally must conduct its meetings in public, small groups of members have been discussing various proposals in private in an effort to take the negotiations away from the glare of the public spotlight.

So far, this technique has proved successful. The panel has been able to work out recommendation on the low-wage exemption, "tandem" contracts and other issues that both sides later could support unanimously.

Panel Chairman John T. Dunlop, former secretary of Labor, has scheduled another meeting of the committee for Dec. 18 to take up the guidelines issue, with at least some hope among participants that the question can be resolved.

The Carter administration established a 7 percent wage guideline during the program's first year, which began in October 1978, and tentatively has boosted that to 8 percent this year pending a recommendation by the committee.

The low-wage exemption now in force excuses workers who earn $4 an hour or less. In yesterday's debate, labor members were seeking to boost this to $6 an hour, while management members wanted to retain the current cutoff.

The labor and management sides also are split over the question of how closely the Pay Committee should review individual wage-increase cases in which employers and unions are cited for violations.

Labor wants the committee to serve as a final review authority in such cases, presumably to give union leaders more bargaining power. However, management representative on the panel want the committee to stick only to broad policy.