The state of emergency under which Bangladesh has lived for nearly four years was formally ended last night, and the first of about 730 prisoners currently being held under it were freed from jails today.

Dispatch riders have been taking written orders for the releases to prisons throughout the country. Those held include people suspected of subversive activities, black marketeers and hoarders.

President Ziaur Rahman, who proclaimed the emergency Dec. 28, 1975, signed the order revoking it to fulfill a commitment he made before general elections in February.

A government spokesman said that, in effect, the ending of the emergency merely formalized a situation which has existed since the election.

"Since the elections, people have had the right to stage processions; trade unionism was allowed; they could go on strike and hold meetings everywhere they liked, although on paper the emergency contined," the spokesman said.

Zia has now carried out all his pre-election promises to put the country on a more normal civilan democratic course.

Zia has resigned his post of army chief of staff although he still lives in his old army house in the cantonment rather than in the presidential residence, and his links with the military appear to be as strong as ever.

As a civilian, he is supreme commander of the armed forces only by virtue of being president.

Martial law has been lifted, and a parliament elected. The president's Bangladeh Nationalist Party, which won a massive victory in the elections, has 205 members in the 300-seat parliament. How ever, the new parliament has only met for two sessions and has been in recess since July. The next session is not expected to begin until the end of January.

The reason given for this is that the parliamentary microphone system is faulty and is being replaced.