Jesse L. Jackson's 1984 national presidential campaign committee and two state affiliates have been fined $13,000 by the Federal Election Commission for underreporting their fund-raising and spending and filing incomplete accounts of their financial activities, the FEC disclosed Monday.

The campaign committees agreed to pay the fine, but maintained that the reporting problems were inadvertent and were eventually corrected. They said the problems were caused by inexperienced volunteers who were participating in a presidential campaign for the first time.

The $13,000 fine is far less than the $368,000 fine former vice president Walter F. Mondale's 1984 campaign committee paid to settle a complaint over its use of delegate committees during the 1984 primaries.

The complaint against the Jackson campaign was generated by a routine audit. It charged that the three committees had:

Underreported their spending by $1.09 million and their fund-raising by $825,959.

Accepted contributions from 29 individuals that exceeded the legal limit of $1,000 per person. The excess totaled $5,561. Accepted $5,850 in contributions from a corporation.

Failed to properly itemize contributions totaling $58,049.

Jackson raised and spent more than $7.8 million on his 1984 campaign, according to FEC records.