The Carter administration yesterday began relaxing portions of its 7 percent wage guidelines to provide relief for hard-pressed businesses while it negotiates with organized labor over whether to set up a new Nixon-style pay board.

Officials of the Council on Wage and Price Stability announced they will begin granting exceptions allowing employers in competitive labor markets to grant catchup raises to workers not covered by standard cost of living clauses.

pthey said they also plan to ease standards for companies with large proportions of low paid employes and for government workers who receive so-called "step" increases.

The moves are part of an effort to prevent businesses from abandoning the current voluntary program while the administration continues its talks over the pay board issue.

Officials had planned to unveil new wage-price standards this week, but postponed that indefinitely for fear of jeopardizing the negotiations with labor on the pay board issue.

The new hope is to make the revised guidelines public before Sept. 30. The second year of the wage-price program begins on Oct. 1.

Many businesses had counted on prompt unveiling of the new guidelines this week to avert a financial pinch. Some firms had complained that the current standards, established almost a year ago, were crimping their profits unduly. In initial comments on the second year program, many firms sought more liberal pay guidelines.

The major reason for the postponement is that the standards themselves are an issue in the talks with labor.