Without conceding any violation of the election laws, the Mondale for President Committee has just agreed to repay the Treasury $379,640 plus a civil fine of $18,500. The settlement was made, explains Michael S. Berman, the campaign treasurer, in order "to avoid protracted litigation over this matter." The case was before the commission because of two separate complaints against the Democratic candidate, one filed by his opponent for the nomination, Sen. Gary Hart, and the other by the National Right to Work Committee.

Federal law provides for the public financing of presidential campaigns only if certain conditions are met by the candidate. He must agree to a national spending limit and to limits in each state. He can accept no more than $1,000 from individual contributors and $5,000 from each political action committee. Mr. Mondale ran into trouble during the primaries because he spent heavily for the first contests in the expectation that the nomination would be won early. When he came close to reaching his expenditure limit, he sought new ways to finance the campaign, and the formation of delegate committees presented an opportunity. Such committees could raise funds for the election of Mondale delegates to the convention -- which indirectly aided the candidate, of course -- and as long as they were not affiliated with the candidate, their contributions and expenditures would not be attributed to his campaign. Last spring, this device worked particularly well for Mr. Mondale in industrial states such as New York, Pennsylvania and Illinois where union PACs contributed heavily to delegate committees instead of to the Mondale for President Committee. But Sen. Hart cried foul, and by the end of April, Mr. Mondale decided his best course was to "termnate" all 124 committees that had been created to help elect delegates pledged to support him.

The Mondale people do not now concede that these delegate committees were actually affiliated with them. For purposes of the conciliation agreement with the FEC, however, they agree to treat the committees as such and to treat both contributions to and expenditures by these committees as their own. Two Republican commissioners voted against accepting this agreement, believing that a full-scale commission investigation was warranted. But the majority and the Mondale campaign representatives concede that some of the committees would probably be found to be affiliated with the national campaign and some would not. The proc could have taken years.

Legal questions in this relatively new field are close. The settlement does not resolve the difficult issues here for future candidates, but it sends a warning that creative financing, even if it's lawful, can ultimately be costly.