Former Alexandria vice mayor James P. Moran, who resigned in June after pleading no contest to a conflict-of-interest charge, said in an interview yesterday he plans to run for city council this spring.

Moran's decision, which he said he will make formal in early January, was widely expected in Democratic Party circles. It puts to rest speculation that he might run for mayor and oppose his former political mentor, incumbent Democrat Charles E. Beatley.

Moran said he is delaying announcement of his candidacy until he gets reaction from a letter sent this weekend to residents who voted in the city's 1982 elections.

The two-page letter, the mailing of which was financed by a group called "Friends of Jim Moran," does not shed any new light on events surrounding his resignation after a special prosecutor said Moran had a business relationship with a developer seeking a contract with the city.

Moran, who was found guilty of a misdemeanor violation of the state's conflict law, closes the letter with what comes close to an admission of guilt. A "perception of me as indispensable to this city and blameless in my actions is a false one," the letter stated. "I doubt that anyone is indispensable to a great city like Alexandria, but I know that I am not. Neither was I without fault in what transpired. A more careful, scrupulous standard of conduct would have prevented the set of circumstances that eventually led to my resignation."

Moran's entry in the race will further add to what is becoming a crowded field of Democratic candidates for the seven-member council. All four Democratic incumbents are expected to run again. In addition, Craig Coverdale, an unsuccessful congressional candidate this year, and Del Pepper, a former aide to Beatley, have announced their intentions to run for city council.