Vernon A. Walters, the State Department's chief diplomatic trouble-shooter, and Max M. Kampelman, a Washington attorney who has performed diplomatic missions for the Reagan administration, appear to be the leading candidates to succeed Jeane J. Kirkpatrick as U.S. ambassador to the United Nations, administration sources said yesterday.

The sources stressed, however, that President Reagan is not expected to make a choice until late February or early March and several other candidates are under consideration, although Walters and Kampelman are considered to be the front-runners.

Frank Shakespeare, former head of the U.S. Information Agency, and Transportation Secretary Elizabeth Hanford Dole also have been discussed seriously for the post. Both Walters and Kampelman are regarded as people who would continue Kirkpatrick's tough and conservative approach to the U.N. job.

That is an important consideration for the president. The Republican right has expressed concern about Kirkpatrick's expected departure from the administration and fears that conservatives are being purged from policy positions in the State Department.

Walters, a retired general and former deputy director of the Central Intelligencce Agency who has served as the State Department's ambassador-at-large since 1981, reportedly has strong backing from Secretary of State George P. Shultz, who the sources said is anxious to bring the U.N. mission firmly under the department's control.

However, the sources continued, while Walters is regarded as loyal to Shultz, he is understood to have expressed unwillingness to accept the U.N. ambassador's post unless it retains the Cabinet rank that Kirkpatrick enjoyed.

The ambiguities caused by Kirkpatrick's status as a subordinate to the secretary of state in some respects and his equal in others led to tensions between Kirkpatrick and Reagan's first secretary of state, Alexander M. Haig Jr., and, to a lesser extent, Shultz.

Kampelman, who represented the United States in conferences stemming from the Helsinki accords on European security and cooperation, is regarded as having strong political and philosophical affinities to Kirkpatrick.

Like her, he is a Democrat who had close ties to the late Democratic senator and vice president, Hubert H. Humphrey, but who has differed in recent years with the Democratic Party's position on such foreign policy issues as taking a tough line in dealing with the Soviet Union and the proper U.S. role in the Third World.

Kirkpatrick has agreed to remain in the U.N. position until March to help ensure an orderly succession, and the sources said Reagan has promised to give great weight to her views in choosing a successor.

Although she is an old friend of Kampelman, the sources said they had no sign that Kirkpatrick is backing him for the job. Sources said she believes that both Walters and Kampelman would handle the U.N. post in a manner compatible with her views.

The sources said others who have expressed a desire for the U.N. job or who have been mentioned in administration discussions include:

Evan Griffith Galbraith, ambassador to France; Maxwell M. Rabb, ambassador to Italy; John A. Gavin, ambassador to Mexico; William A. Wilson, ambassador to the Vatican, and former Senate Foreign Relations Committee chairman Charles H. Percy (R-Ill.), who was defeated Nov. 6.

However, the sources said, none of these candidates is considered likely to get the job.

In related personnel actions, administration sources said yesterday that Lewis A. Tambs, the outspokenly conservative ambassador to Colombia, will become ambassador to Costa Rica, instead of being dropped from the administration as his backers had feared.

The sources also said that L. Craig Johnstone, a deputy assistant secretary of state who withdrew last week from consideration as ambassador to Honduras, will become ambassador to Algeria and that Charles A. Gillespie, another deputy assistant secretary, will become ambassador to Bolivia.

The sources said another conservative, J. William Middendorf II, who has been serving as ambassador to the Organization of American States, has been offered the ambassadorship to the European Economic Community, which has headquarters in Brussels, but is being urged by fellow conservatives to reject the offer.

The sources said conservatives want Middendorf to remain in a policy position in Washington and view the EEC post offer as an attempt by Shultz to sidetrack him.