LOS ANGELES (AP) _ A municipal judge who faces recall as presiding judge arranged for her goddaughter's unlawful release from custody after the teen-ager's arrest in an assault investigation, a district attorney alleges.

A memo written by Deputy District Attorney Robert N. Jorgensen accused Municipal Court Judge Maxine Thomas of appearing to violate the Code of Judicial Conduct by signing an order releasing her 18-year-old goddaughter, Tiffany Webb.

Calls to Ms. Thomas for comment today were not returned. The Los Angeles Times, which reported on the memo today, said Ms. Thomas also did not respond to several requests by its reporter for comment.

A sealed petition was filed Tuesday that forces a June 25 recall vote against Ms. Thomas, 38, in her post as presiding judge. The petition was signed by 42 of the Municipal Court's 80 judges, said Frederick K. Ohlrich, chief deputy court administrator. A majority of 41 was required to force a vote.

Ms. Thomas, the first black woman elected by her colleagues as presiding judge, would lose that position but remain on the court if 41 judges also vote against her at the meeting. Municipal Court judges are elected. The post of presiding judge usually has a one-year term; she assumed the position in January.

Other Municipal Court judges contend Ms. Thomas used her position as presiding judge as a springboard for a Superior Court election campaign, played favorites in making court assignments and was frequently absent.

The incident concerning her goddaughter occurred in May 1985. Jorgenson's memo said Ms. Thomas signed an order freeing Ms. Webb without bail and that Ms. Webb failed to sign a required agreement promising to make court appearances.

Prosecutors eventually dropped the charges against Ms. Webb.

Deputy District Attorney Steven A. Sowders, to whom the memo was addressed, said he interviewed the judge and decided to let the matter rest on the grounds it was an isolated incident based on a misunderstanding.

At an April 14 news conference, Ms. Thomas claimed support of nearly 90 percent of the Municipal Court judges and suggested criticism of her was politically motivated.

She faces a runoff election for Superior Court in November. She received 32 percent of the primary vote among four candidates while her November opponent, Burbank Municipal Judge Bernard Kaufman, got 37 percent.

Ms. Thomas was rated ''not qualified'' for the Superior Court bench by the Los Angeles County Bar Association.

Before the recall petition was filed, the National Association for the Advancement of Colored People spoke out on Ms. Thomas' behalf.

''We demand an immediate investigation by the Fair Political Practices Commission into this smear campaign, a campaign which will ultimately tarnish the image and efficiency of the entire judiciary,'' said Willis Edwards, president of the Beverly Hills-Hollywood NAACP.