Three weeks ago today, Rep. David R. Obey (D-Wis.) and two colleagues announced renewal of their efforts to put a lid on the influence of political action committees and contributions they can make to House candidates.

Three days later, the Congressional Black Caucus-Political Action Committee sent a letter signed by its executive director, David Greene, to officials of other PACs. It warned that "a major push is now under way to further control and limit the growth of political action committees as we now know them.

"This move must not be taken lightly," the letter said. In it, Greene asked for "a strong letter of support for the continued existence of PACs as we now know them" and "a donation of $5,000 as soon as possible" to help counter the threat.

The request has been criticized for several reasons, not the least of which is that several caucus members--including Rep. William L. Clay (D-Mo.), CBC-PAC chairman, and Rep. Louis Stokes (D-Ohio), CBC-PAC treasurer--have signed up as co-sponsors of the Obey bill.

The CBC-PAC letter's stationery, which includes the names of all 21 caucus members and the motto, "We have no permanent enemies/We have no permanent friends/Only permanent interests," lists "Suite 600, 200 C St., S.E." as CBC-PAC's address.

There is no such office, and the building at 200 C St. SE, which houses a new luxury hotel called the Capitol Hill, stops at the fifth floor.

Jonathan Z. Rubin, the hotel's sales and marketing director, said he gave Greene the suite number to use as a mail "drop" in anticipation of his business. "He Greene came in about six weeks ago," Rubin said. "He's apparently starting up a PAC, and he needs an office on the Hill. He said a PAC can't be housed in a congressional building . . . . He said he's going to do business with me."

The hotel's suites cost $2,100 to $2,900 a month, more than the CBC-PAC usually took in during 1982, its first full year in business. Rubin said Greene told him a decision on whether the CBC-PAC would rent a suite "would be made by July." Meanwhile, Rubin said, he told Greene to use "Suite 600" for his mail.

Last Friday, as Greene was leaving Clay's office in the Rayburn House Office Building, he refused to say where the CBC-PAC, of which he said he is "full-time" executive director, has its headquarters.

Greene also refused to say whether he had received money as a result of the fund-raising appeal. To most questions, he responded, "No comment. Any information generated on that would have to come from the chairman."

Although the CBC-PAC letter appears to suggest opposition to Obey's "clean campaign act" and to ask for money on that basis, Greene said, "I don't read it that way." Asked how, as its signer, he did read it, he said, "Any comment on that would have to come from the chairman Clay ."

Clay, formally added to the list of the Obey bill's co-sponsors April 18, could not be reached for comment despite repeated attempts to contact him.

However, Stokes said he "saw it the letter before it went out" and saw no inconsistency between it and Obey's bill, which he joined as a co-sponsor last Monday.

Stokes cited a segment of the letter that said: "The CBC-PAC is currently mounting a campaign designed to acquire support for allowing political action committees to continue to function, even though we may support some moderate adjustments over the medium and long term."

Said Stokes: "I think that the letter, which was sent out by the executive director of the PAC, makes it clear that we support some form of change with reference to the PAC situation." As for Obey's bill, Stokes said, "I still support it."

Obey's bill, prepared with the self-designated citizens' lobby, Common Cause, would limit to $90,000 the amount that a House candidate could accept from PACs in a two-year election period and establish partial public financing for congressional campaigns. A semi-monthly newsletter entitled "PACs & Lobbies" described it as an "anti-PAC bill."

In appealing for funds and support, the CBC-PAC letter told other PAC officials that "you have surely noticed that our PAC consists entirely of congressmen" and assured them that their letters of support "will definitely be channeled into influential congressional hands sympathetic to the existing PAC philosophy."

In seeking $5,000 contributions, the letter added that "we are a multi-candidate PAC . . . . We perceive the threat to existing PACs as real even if misdirected and the need for funds to finance candidates who support our position in this matter is essential . . . . PACs need to wield a unified sword from a position of political and economic strength."

Asked how that squared with Obey's bill, Stokes said: "The Obey bill is not yet law. We don't know whether it will become law or not. The CBC PAC is trying to exist under the current situation . . . ."

Asked if the letter is consistent with support for Obey's bill and what "threat" to the PACs was seen by the CBC-PAC, Stokes said, "I don't want to discuss it further. I've answered you the best I can."

Rep. Parren J. Mitchell (D-Md.), added to the list of Obey bill co-sponsors April 20, said he was not aware of the letter and said of Greene, "I don't even think I know him."

Formed in December, 1981, with a post office box for an address, the CBC-PAC notified the Federal Election Commission March 17 that it had qualified as a "multi-candidate committee"--meaning it had been in business for six months, received at least 50 individual contributions and contributed to at least five candidates for federal office.

The achievement, recorded about the time Greene reportedly inquired about a suite at the Capitol Hill, entitled the group for the first time to donate $5,000, rather than $1,000, to each candidate in an election.

Two caucus members, Reps. Ronald V. Dellums (D-Calif.) and John Conyers Jr. (D-Mich.), co-sponsored the Obey bill at the outset. They could not be reached for comment about the CBC-PAC letter, although aides to Dellums doubted he knew of Greene's fund-raising pitch.

Del. Walter E. Fauntroy (D-D.C.), a caucus member who is not a sponsor of Obey's bill, could not be reached for comment.

Robert C. Heckman, chairman of the Fund for a Conservative Majority, received the letter and said he is particularly perplexed by the fact that some caucus members had endorsed Obey's "anti-PAC bill."

"It would be hard for me to conclude anything but the fact that you are trying to solicit money and support in a clearly fraudulent manner," Heckman wrote Greene last Wednesday. He said he intended to complain to the FEC.

Heckman took special exception to the observation in Greene's letter that the CBC-PAC consists entirely of congressmen. "In light of that fact," Heckman wrote, "I find your appeal that much more appalling."

Attached to the fund-raising appeal was a one-page excerpt from a defense of PACs written for the Heritage Foundation by Paul D. Kamenar, litigation director of the conservative Washington Legal Foundation. The CBC-PAC letter said the excerpt was "reproduced with permission from the author, Paul D. Kamenar." Kamenar said he gave no such permission and is demanding a retraction from Greene.

At the other end of the spectrum is Common Cause president Fred Wertheimer, who favors passage of Obey's bill but acknowledges that it faces "a very tough political fight."

"It shows how damaging this PAC system is and how crucial it is to change it," Wertheimer said of the CBC-PAC appeal. "The PAC system is a process that has become so destructive to the institution of the Congress that in some ways, the members themselves have the highest stakes in getting out from under the shadow it casts . . . ."

Despite his reluctance to comment, Greene was more voluble earlier Friday before being approached by a reporter in Clay's office. Responding to an earlier call from another reporter, Greene said several times that he initiated the letter without bringing it to the attention of caucus members. He said he wanted to get a reading from other PACs first.

"It's kind of disappointing," Greene said of Heckman's reaction. "It seems to me he should have called me up, asked to go out to lunch, and said, 'I welcome you joining the free-enterprise system.' "