Councillor John J. McNamara bolted the City Council independents' ranks this week to keep fellow-councilman Edward J. Sullivan from becoming Cambridge's new mayor. The Cambridge Civic Association, meanwhile, abstained from voting and let the independent majority bring the newly-elected council's first meeting to an impasse.

Councillor Hyman Pill explained the CCA's abstention by asserting that the association's minority will "wait and see" which independent will agree to cooperate with CCA-backed city manager John J. Curry '19 and uphold CCA school committee policies. Joseph A. DeGuglielmo '29, unofficial spokesman for the CCA group, said yesterday that "any of the five independents might be acceptable, but the CCA will make sure that he's the man we want before we pick him."

Reliable sources predicted that the CCA will not endorse its arch foe Sullivan, and that McNamara--a strong supporter of the urban renewal program--is most likely to receive CCA support. Present misunderstanding between him and Curry can easily be reconciled the source added.

Independent John D. Lynch, a former mayor of Cambridge, said yesterday that he would not want the mayoralty "if it takes a political deal to get me in." He added that he supported Sullivan.

The CCA's determination to pick the new mayor is due largely to the fact that the mayor is also chairman of the School Committee. This group is now evenly divided between the CCA-endorsed members and independents, so that the mayor will have the deciding vote. The association is also anxious to have a mayor who favors urban renewal.

The CCA was responsible for electing Cambridge's last mayor, John J. Foley, also an independent. The new council will meet on Monday evening for another try at electing the mayor. Pill said that he expects the meeting will elect the mayor, but DeGuglialmo expressed doubt.