Seven Cambridge patrolmen asked the Middlesex Superior Court April 30 to extend the police department's current civil service list, which ranks patrolmen for promotion, for another 13 months.

If the list is continued, patrolmen could be promoted without having to retake the civil service exam in competition with new patrolmen.

The list, due to expire April 30, has been suspended for 13 months starting in 1974 in response to a suit brought by a group of black patrolmen who wanted more black sergeants. The city bypassed the list until the number of black sergeants was increased to a representative level.

Two other patrolmen were passed over for promotion when the list was reinstituted. They have filed $100,000 damage suits in U.S. District Court claiming that their equal opportunity rights were violated when 25 patrolmen with lower exam scores received promotion ahead of them.

Patrolmen Edward Hussey and Peter DeLuca achieved the fourth and fifth best scores on the exam but have not yet been promoted to sergeant, James Pool, DeLuca's attorney, said yesterday.

Brian J. Mcmenimen, Hussey's attorney, said yesterday that Hussey was not promoted because of a personal bias against Hussey on the part of the late Chief Francis A. Pisani and others within the "power structure."

DeLuca was one of two officers who arrested Lawrence Largey, aged 17, on October 21, 1972, on charges of drunkenness and assault. When Largey was found dead in his cell three hours after his arrest the Largey family sued the city, alleging that he had been brutalized.

If DeLuca was bypassed because of the pending Largey case he should be given a hearing so that he can clear himself, Pool said.

A city hearing into the case has been postponed until the Largey suit is settled.

James L. Sullivan, city manager, said yesterday that the promotion decisions were made by Pisani on the basis of a rating system that included more than the "numerical" results of the civil service exam.