A children's television watchdog group, upset over the growing number of commercials aimed at youngsters, wants the government to reinstate limits on such advertisements.

Action for Children's Television, in a petition filed Wednesday with the Federal Communications Commission, said 22 percent of the total time devoted to children's programming now consists of commercials.

Before the FCC decided to scrap its guidelines on children's TV ads in 1984, an action that a federal appeals court has ordered the agency to review, broadcasters were limited to 9 1/2 minutes an hour on Saturday and Sunday mornings -- children's "prime time" -- and 12 minutes an hour on weekdays.

"Broadcasters currently are exceeding those limits substantially," said Donna Lampert, an attorney for the group, asserting that some stations cram 16 minutes of advertisements into each hour of weekday-afternoon children's shows.

Independent stations air the most commercials, Lampert said, crediting the three major networks for generally sticking with the old limits.

Lampert said ACT is asking the commission to reinstate immediately the original weekend limit and to expand the concept of children's prime time to include weekday afternoons, when many children watch.

"The time has come to stop using children as a target for commercials," said Peggy Charren, president of the nonprofit nationwide group based in Boston that for almost two decades has fought for stronger children's TV guidelines.

Charren said that although the FCC already is under court order to reconsider its position on children's commercials, ACT's petition was timed to coincide with the fall TV season.

Bill Johnson, acting chief of the FCC's mass media bureau, said the agency is working on the current court request but expressed doubt that the commission would return to the old standard for children's TV without new evidence.

In fact, he said, there never was a federal 9 1/2-minute rule; it was an industry code endorsed by the FCC in 1974.

The lifting of the children's TV regulations was part of the ongoing FCC drive under the Reagan administration to loosen restrictions on U.S. broadcasting.

Last month, the commission repealed the 38-year-old "Fairness Doctrine," which required broadcasters to air all sides of controversial public issues. Members of Congress have vowed to fight that decision with legislation