An article yesterday incorrectly stated the position of Sen. Charles McC. Mathias Jr. (R-Md.) on an amendment sponsored by Sen. Christopher J. Dodd (D-Conn.) in the Foreign Relations Committee that would have barred the use of U.S. foreign aid to help Nicaraguan rebels. Mathias voted for the amendment.

The chairman of the Senate Foreign Relations Committee and Sen. Claiborne Pell (D-R.I.) disagreed strongly yesterday about how far a vote to bar use of foreign aid to help antigovernment rebels in Nicaragua goes toward putting the aid money off limits to the rebels.

In fact, Chairman Richard G. Lugar (R-Ind.) and Pell, the committee's ranking minority member, could not even agree on which of two versions of an amendment on aid to the rebels, called "contras," had been adopted by the committee Wednesday night when it approved a $12.8 billion foreign aid bill for fiscal 1986.

In foreign policy terms, the dispute potentially involves far more than a procedural misunderstanding.

At issue is whether the amendment, adopted by a 9-to-8 vote, prohibits agreements that would enable other countries receiving U.S. aid to give some of that aid to the contras.

That issue has major policy significance because of persistent but unconfirmed reports that some aid provided to Honduras and El Salvador has been diverted to the rebels fighting Nicaragua's leftist government. Reagan administration officials also reportedly have been considering channeling money through third countries as an alternative to renewed covert funding for the contras.

The amendment is unlikely to survive in the full Senate, sources said, because Lugar will explain that there is disagreement about which amendment was adopted in committee. He is likely to prevail with a request that the Senate strike the disputed measure from the bill.

The confusion about what happened Wednesday night began after the committee, by an 8-to-8 vote, rejected a two-part amendment proposed by Sen. Christopher J. Dodd (D-Conn.). The first part of the Dodd proposal specified that aid appropriated for fiscal 1986 "may not be obligated or expended for the purpose of supporting . . . directly or indirectly, military or paramilitary operations in Nicaragua by any group, organization, movement or individual."

However, Republican members were unanimous in opposing Dodd's second paragraph, which said: "None of the funds . . . may be obligated or expended for assistance to any country which provides funding or material support for military or paramilitary operations in Nicaragua by any group, organization, movement or individual."

According to the stenographic record of committee deliberations, Pell then said he wanted to offer an amendment "that might meet some of the objections because it is virtually the same as the Dodd amendment, except that it does not prohibit the giving of aid to third countries that might in their wisdom, or lack of wisdom, want to assist the contras."

Dodd asked, "As I understand it, what my colleague is doing is just taking out the second paragraph of my amendment?"

Pell replied, "That is essentially what it does."

Just before the vote, Lugar stated that it was his understanding that Pell's amendment "essentially is explained as part of the amendment we just defeated." Aides to Lugar said subsequently that the chairman thought that Pell was proposing the same amendment as Dodd, minus the second paragraph barring the channeling of aid through third countries.

When the vote was taken, one Republican senator, Charles McC. Mathias Jr. (Md.), joined with the committee's eight Democrats to adopt the amendment.

Afterward, however, Pell said his amendment was not a truncated version of the Dodd proposal but had different language. It stated that aid funds cannot be used "directly or indirectly" to help "any person or group engaging in an insurgency or other act of rebellion" against the Nicaraguan government. But it also added:

"The United States shall make no agreement and shall enter into no understanding, either formal or informal, under which a recipient of U.S. economic or military assistance or a purchaser of American military equipment shall provide assistance of any kind to persons or groups engaging in an insurgency or other act of rebellion against the government of Nicaragua."

Aides to Lugar said he never saw that language during the debate Wednesday night and did not become aware of it until yesterday. But a statement issued yesterday on Pell's behalf said "printed copies of his amendment and a clear explanation of its meaning were before each member of the committee when the vote was taken."