A select parliamentary committee officially cleared the government today of charges that its sinking of the Argentine cruiser General Belgrano during the 1982 Falklands War was militarily unjustified and politically motivated.

The seven-member committee majority, in a report issued after more than a year of hearings on extensive parliamentary and press allegations, also concluded that the government had not engaged in a cover-up following the sinking, in which 368 Argentine sailors died.

A minority report, however, sharply disagreed with the official document and described the decision to sink the Belgrano as "hasty and unjustifiable." The four committee members from the opposition Labor Party accused Prime Minister Margaret Thatcher and her government of "palpable negligence" in an effort to stay in power.

The minority said the government's refusal to allow classified information to be included in the report, and the refusal of Thatcher to testify, implied a continuing cover-up.

The Belgrano issue last year led to prosecution of a Foreign Ministry official, Clive Ponting, for leaking documents that undermined the government position. Ponting's subsequent acquittal directly challenged the scope of Britain's Official Secrets Act in a way that has still to be resolved.

The sinking of the Belgrano came on May 2, one month after Argentina had invaded the British territory off the South American coast. Britain had sent a naval task force, and had declared a 200-mile exclusion zone around the islands. The Belgrano was outside the zone, however, and for several hours had been traveling away from the Falklands.

The government's case, as presented to and accepted by the committee's majority, was that the War Cabinet secretly had changed Britain's "rules of engagement," specifically authorizing the sinking of the Belgrano outside the zone. Additionally, government ministers testified that news of the change of direction of the Belgrano had not reached them from the military at the time the attack was approved.

Regardless of the Belgrano's direction, the government argued that the decision was justified by intelligence information indicating Argentina intended to attack the British naval task force in the vicinity and that the Belgrano would play some part in that attack.