Congressional candidates received a record $93.7 million from political action committees during the first 18 months of the 1989-90 election cycle, the Federal Election Commission reported yesterday.

Democrats, who control Congress, easily outdistanced Republicans, receiving more than $59 million from PACs compared with more than $34 million for GOP candidates. The money was given to House and Senate candidates seeking election in the current two-year cycle.

Most PACs are formed by special-interest groups, labor organizations and corporations. They give to Democrats more often because the party has all the committee chairmen and the leaders who determine the legislative agenda.

The latest figures were released at a time when Congress is moving to curb spending on congressional elections. However, the Senate and House have passed separate versions of campaign finance reform and a politically difficult compromise must still be worked out.

The FEC study, covering contributions from January 1989 through June 1990, said the record $93.7 million total compares with $88 million in the first 18 months of the 1987-88 election cycle.

The new figure represents a dramatic increase from the $71 million given to congressional candidates in the 1985-86 cycle.

Corporate PACs led all categories, contributing $35 million to federal candidates, followed by the $26 million contributed by PACs in the combined category of trade associations, membership organizations and health groups. Labor PACs were next with $20 million.

The study also showed that overall PAC spending increased by 8.3 percent, to $233 million, in the first 18 months of the current cycle. PAC receipts rose 3.3 percent to $275 million.

Most PAC contributions, $79 million, went to incumbents, while $6.5 million went to challengers and $8.1 million to those running for open seats.

The FEC reported 4,590 PACs collected and distributed contributions in the current cycle. It also reported that 1,939 of the PACs were affiliated with corporations, while 783 were categorized as trade, membership and health groups. There were 370 labor committees.

More than $66 million of the PAC contributions went to House candidates, while $27 million went to candidates for the Senate.

The FEC said the most money collected by a PAC was $8 million, by the Teamsters-run Democratic Republican Independent Voter Education Committee. The American Medical Association Political Action Committee was next, collecting $4.7 million.

The Teamsters organization also spent the most, $6.4 million, followed by the AMA's PAC, which spent $3 million.

American Telephone & Telegraph's PAC led corporate committees, collecting more than $2 million, followed by the Federal Express Corp. PAC with just over $1 million. The two PACS also led corporate disbursements.