Sen. Lloyd Bentsen (D-Tex.), chairman of the Senate Finance Committee, is the 1987 fund-raising champion among senators facing reelection this fall.

Bentsen, who is expected to have little difficulty being reelected, raised nearly $4.6 million last year, including nearly $1.3 million from political action committees (PACs), according to figures that Common Cause compiled from Federal Election Commission reports.

A Common Cause spokeswoman noted that the chairmanship of the tax-writing Finance Committee was the place to be in the last Senate election cycle as well. Sen. Bob Packwood (R-Ore.), then the chairman, raised about $5 million in 1985.

Bentsen also has the most cash on hand starting the election year, $4 million. Sen. Howard M. Metzenbaum (D-Ohio) is close behind with $3.8 million, and Sen. Pete Wilson (R-Calif.) has $3 million; Metzenbaum and Wilson face tough general election challenges. Sen. Paul S. Sarbanes (D-Md.), who so far doesn't face a tough challenge, has $472,202 in the bank, one of the lowest totals of the 27 incumbents running this fall.

The Common Cause study, released today, found that 16 of the 27 senators raised more than $1 million during 1987. And 21 of the 27 received $300,000 or more from PACs, the study found.