The new Cambridge City Council, chosen in last fall's municipal election, will take its first official action this morning when, following inauguration ceremonies at 10 a.m., it begins the job of selecting one of its nine members as Mayor for the succeeding two-year term.

Latest indications show the horse race listing no distinct favorites. Of the three most serious contenders--present Mayor Thomas M. McNamara, Walter J. Sullivan, and present vice-Mayor Alfred Velucci--the latter has several times shown an overt interest in the post.

There are possibly three more Council members "casually interested" in the job, and, it would seem, none of the nine would be adverse to accepting the Mayoralty honor.

One factor against McNamara, as well as against former Mayors Edward A. Crane '38, Joseph A. DeGuglielmo '29, and John D. Lynch, is the long-standing Cambridge tradition to pass the Mayor's position around the Council before selecting someone for a second term. This quirk will presumably affect McNamara the most, since he has just been Mayor and the other three are not actively campaigning.

Ballotting will begin this morning, under the aura of frequent criticism against the City for dragging out its Mayoralty elections. On one occasion ballotting lasted until mid-April. In 1958, however, McNamara was chosen in 15 minutes.

The four Councillors elected under the Cambridge Civic Association's banner have apparently not organized behind any one candidate.

Having won three of six seats on the School Committee, the CCA does not want the Mayor, who presides and casts deciding votes at Committee meetings, to be inimical to the Association's interests.

One source said that as best he knew the battle would be a free-for-all, with no telling beforehand of the outcome. He said he knew of no commitments or blocs.