The State Department and a group of conservative senators, at odds over U.S. policy toward the Marxist government of Mozambique, are now deadlocked on the nomination of a new U.S. ambassador to that war-torn southern African state.

Spokesman for the two sides said yesterday that neither side backed off during a meeting Tuesday between Secretary of State George P. Shultz and the two senators leading the opposition, Minority Leader Robert J. Dole (R-Kan.) and Jesse Helms (R-N.C.), the Foreign Relations Committee's ranking Republican member.

"Neither side gave any quarter," said Tom Boney, Helms' press spokesman.

The State Department declined comment on the Shultz-Dole-Helms meeting. But one U.S. official readily concurred with the Boney assessment, adding, "It sounds like a deadlock."

Caught in the policy cross fire is Melissa F. Wells, who was nominated by the White House last October to become ambassador to Mozambique and whose approval by the Senate has been blocked since March, mainly by Helms and Dole.

The dispute centers on whether the United States will extend recognition to the Mozambique National Resistance (RENAMO), the movement leading a widespread insurgency against the Mozambican government. Despite Mozambique's self-description as a Marxist-Leninist state, the United States has maintained good relations with the country since its independence in 1975.

The only point Helms and U.S. officials agreed upon following the Tuesday meeting was that the State Department is still steadfastly refusing to recognize RENAMO.

Both sides expressed agreement that a meeting held here between a midlevel department official in late June with a RENAMO representative to discuss the release of an American missionary nurse, Kindra Bryan, seized in a war zone May 13, did not constitute "recognition" of the rebel group or any shift in U.S. policy.

Earlier this week, Shultz wrote a letter to Dole, and sent copies of it to other interested senators, explaining the administration's policy toward Mozambique and RENAMO in an apparent attempt to convince them to drop their opposition to Wells' nomination.

Shultz also took the unusual step of going to Capitol Hill to meet with Dole and Helms in the Senate minority leader's office Tuesday for the same purpose.

Wells' confirmation troubles were highlighted in early May, when 28 senators, most of them Republicans, opposed bringing her nomination up for a vote on the floor. Since then, Helms, with Dole's support, has kept Wells' nomination from coming up again, hreatening a filibuster if it does.

The Senate Democratic leadership, which is generally sympathetic to Wells' nomination, has not sought a confrontation largely because it sees that Republicans are divided on the matter and because Democrats are in no mood to battle on behalf of a White House appointee.

Helms has insisted he has nothing against Wells personally and will drop his opposition if the State Department recognizes RENAMO "as an organization" and deals with it in the same manner it now does the African National Congress of South Africa.

The latest skirmish in the struggle over U.S. policy toward Mozambique, and Wells' nomination, has come over the nature of recent U.S. contacts with RENAMO to secure the release of the captured American nurse.

Helms had been pressing the State Department to contact RENAMO to obtain its support for Bryan's release, and thus begin dealing with the rebel group as a step toward recognizing it.

In an apparent attempt to satisfy Helms, the department on June 27 sent Greg Fergin, of the Mozambique desk office, to meet Louis Serapiao, the RENAMO representative here, to obtain information he might have on her whereabouts and possible aid to gain her release. Monday, the State Department in a statement confirmed the meeting but said it was for "humanitarian purposes" and limited "strictly" to discussing Bryan's case.

Boney agreed, saying, "Neither side contends the contact constitutes a change in State Department policy." He indicated Helms opposition to Wells' nomination remains as strong as ever.