Special-interest group spending in federal campaigns for 1989-90 fell 2 percent while fund-raising declined 3 percent, the first drop in more than a decade, the Federal Election Commission said Saturday.

Political action committees, which numbered 4,681, raised $372.35 million and spent $358.08 million from January 1989 through last November's election, with the sharpest drop posted by committees without a sponsor, the agency said.Total PAC spending reached a record $364.2 million in 1987-88 and fund-raising peaked at $384.6 million. At the beginning of the decade, spending totaled $131.2 million while fund-raising was $137.7 million.