President Carter, in a bid to build support among Hispanic voters by appointing a Mexican-American as U.S. ambassador to Mexico, is expected to offer the post to former New Mexico governor Jerry Apodaca, informed sources said yesterday.

The sources said Apodaca is the leadig candidate among six persons -- four of them Mexican-Americans -- under consideration for the appointment. -

However, the sources added, the situation has been complicated by the fact that Apodaca, who also has been under consideration to head the new Cabinet-level Department of Education had indicated he does not want the Mexico embassy post.

There have been recent reports that Carter, after taking with Apodaca, had decided against naming him to the education job. But, the sources said, Carter, anticipating a tough contest with Sen. Edward M. Kennedy (D-Mass.) for Hispanic electoral support, wants to get Apodaca into his administration and hopes he will reconsider his position about going to Mexico.

Apodaca was among four persons recommended for the Mexico embassy by Secretgary of State Cyrus R. Vance, the sources said. They identified the others as Esteban Torres, a White House adviser on Hispanic affairs; Viron P. Vaky, who is retiring as assistant secretary of state for inter-American affairs, and Sol Linowitz, negotiator of the Panama Canal treaties and an influential figure in foreign policy circles.

The sources said the White House added to the list Abelardo Valdez, recently appointed as chief of protocol at the State Department, and Graciela Olivarez, head of the Community Services Administration.

Because of the importance that Carter's reelection strategists attach to the Hispanic vote, the sources said it seems almost certain one of the Mexican-Americans will be picked. They added there is a chance the decision will be announced Monday when a group of Mexican-American leaders is scheduled to receive a foreign policy briefing at the State Department.

Public opinion in Mexico traditionally has been hostile to sending an ambassador of Mexican descent to Mexico City. The attitude of many Mexicans was that such a move would be patronizing and paternalistics.

However, the sources said, Mexican President Jose Lopez Portillo, who recently had shown interest in building stronger ties with the Mexican-American community, has been sounded out and has indicated he would support appointment of a Mexican-American.