Cambridge School Superintendent William Lannon presented three alternative plans for racially balancing the city's elementary and middle schools to city officials last night.

The plans, designed to prevent Cambridge schools from avoiding state school integration guidelines and the risk of court-ordered desegregation measures, all involve substantial redistricting, Lannon added.

Two of the plans would move district lines a few blocks in many parts of the city; the third would pair existing schools, using one building for lower grades and the other for upper grades.

Some combination of the plans will be put into effect by the beginning of school next September, Bert Giroux, school spokesman, said yesterday.

A voluntary desegregation plan enacted last year "works to a point but obviously because of population trends, it will not continue to be a valid means" of integrating city schools, Giroux added.

"If no steps were taken, I am sure we would have some response from the state Department of Education," Giroux said.

A recent state report found four of the city's 16 schools--the Fletcher, King, Roberts and Webster schools--racially unbalanced with more than 50 per cent minority enrollment.

Six other schools reported less than 30 per cent minority enrollment, making them "racially isolated." They included the Gore Street School, scheduled to be closed next year, and the Agassiz, Haggerty, Harrington, Kennedy and Peabody schools.

Of those, the Kennedy school, with 5.7 per cent minority enrollment, and the Harrington school, with 11.6 per cent minority enrollment, were the most out of line.

Two weeks of review by the same local committees will follow last night's presentation.

Officials will then invite residents to a city-wide planning meeting in the second week of April. Following that session, Lannon will make his final recommendation to the school committee.