President Reagan yesterday offered an apparent endorsement of covert U.S. aid to noncommunist rebels fighting the Marxist government in Angola.

"We all believe that a covert operation would be more useful to us and have more chance of success right now than the overt proposal that has been made in the Congress," Reagan said.

The president's remark came in response to a question at a meeting with network anchors and columnists in the White House family theater. Reagan also indicated that Secretary of State George P. Shultz was no longer opposed to aid for the National Union for the Total Independence of Angola (UNITA), led by Jonas Savimbi.

While the issue was known to be under debate in the administration, this was the first time Reagan has suggested where he stands on whether to aid the rebels and how.

It was not clear from his remarks whether the administration has made a final decision on the issue, which had been under debate for a number of weeks.

The CIA and Pentagon had pushed for a large covert military operation, while various congressman introduced bills last month that would authorize $27 million in either overt humanitarian or overt military aid.

The State Department at first opposed any aid.

But Shultz was recently reported to have changed his position and now favors a covert rather than an overt program.

Such an approach, he argued, would allow the United States to follow a two-track policy of continuing to seek a negotiated settlement of the Namibia dispute and the withdrawal of Cuban troops from Angola.

Despite the CIA and Pentagon push for a covert military program -- one figure mentioned was $200 million to $300 million -- congressional sources had said a far smaller one of around $30 million was more likely at the start.