After completely ending a hunger strike that had brought some of them to the brink of death, 40 imprisoned terrorists in British-ruled Northern Ireland said today they were ready to abandon the rest of a four-year protest of prison rules.

The climax of the hunger strike came last night when the seven original strikers ended their 53-day protest. Their decision was followed throughout the night and this morning by the other 33 prisoners, who had joined in the fasting this month.

British officials hailed the strike collapse as a major victory since the terrorist failed to win from the British government special status as political prisoners rather than criminal convicts. But by ending their protest the convicted terrorist will become eligible for increased flexibility in regulations on prison clothing, work and privileges for all inmates in Northern Ireland, where three-fourths of the prisoners are convicted terrorists.

Today's statements show that the Irish terrorists have been able to save face sufficiently to make the end of the Maze Prison protest possible. But the terrorist' failure to win status as political prisoners or gain wide Irish Catholic support for the hunger strike appears bound to further erode the terrorists' political and propaganda impact.

They also have been further isolated by increasingly close cooperation between the British and Irish governments on antiterrorist security and a wide range of political and economic concerns easing the strain that has existed since the Irish Republic gained independence a half century ago.

Claiming victory for the prisoners, Gerry Adams, leader of the political wing of the largely Catholic, Irish nationalist group, the Provisional Irish Republican Army, said at a press conference in Belfast that "no one expected the British government to turn around and, on the record, say these men have political status."

But, he added, "toward the finale of the hunger strike what the British government did was to give these men clear political recognition."

He and other provisional IRA spokesmen said the government did this by giving leaders of the protesting prisoners documents detailing flexibility in prison rules. The rules fulfill much of their specific demands about dress, work, association with each other, outside visitors, mail and remission of sentence for good behavior, all part of the preferential treatment generally accorded political prisoners.

They said the convicted terrorists will be able to wear their own civilian clothes and, in place of "penal" work in prison shops, will be able to work at maintaining their own areas of the prisons, join training programs or attend education classes.

British officials said the flexibility in prison rules does not confer special status on the convicted terrorists or represent a concession to their protest because it applies to all prisoners and existed before the hunger strike began.

Details of the flexibility in prison rules were spelled out at length by Humphrey Atkins, Prime Minister Margaret Thatcher's Northern Ireland secretary, in a statement in Parliament that reaffirmed an earlier policy allowing prisoners to wear their own clothes during evening and weekend recreation hours as long as prison-issue "civilian-type clothing" is worn the rest of the time.

Atkins' summary also indicated that prisoners who obey rules will be allowed to associate with each other within each wing of a prison block in the evening and on weekends.

Catholic politicians in Northern Ireland and government officials in the predominantly Roman Catholic Republic of Ireland indicated they thought this could provide the basis for ending the prisoners' protest.

Hundreds of convicted Catholic Irish nationalist terrorists in the Maze Prison outside Belfast have refused in varying numbers since 1976 to work, wear prison clothes or use sanitary facilities, instead covering themselves with blankets and smearing their cells with excrement. Seven of them broadened the protest by beginning a hunger strike Oct. 27. They were joined this month by 33 sympathizing prisoners.

Last night, after Sean McKenna, 26, was transferred, comotose and near death, to a civilian hospital, the other six original hunger strikers asked for food and medication for themselves and McKenna. The other 33 prisoners also resumed eating with breakfast this morning.

McKenna was given three days to live before the hunger strike was called off. He is serving 25 years for attempting to kill a police officer, bombing, kidnaping and other crimes. His six comrades are serving terms ranging from 14 years to life for murder, armed robberies and other violence.

Leaders of the Provisional IRA,said the so-called "blanket" and "dirty" protest also would be phased out beginning next week if the British government began extending to them the promised flexibility in prison rules.

The most popular militant Protestant leader, the Rev. Ian Paisley, today held a stormy meeting earlier this month with Irish Prime Minister Charles Haughey to explore closer institutional cooperation between the two countries, which Irish and British officials hope could eventually lead to a new joint approach to the problem of Northern Ireland.

Despite suspicions voiced today by some Protestant political leaders in Northern Ireland that the British government was giving the protesting prisoners too much, most officials expressed widespread relief that the end of the hunger strike had averted a potentially dangerous crisis.

The prospective end of the rest of the prisoners' protest added to what one Irish Catholic Church leader in Northern Ireland called "a feeling that we may be at the beginning of something really big for the future of reconciliation and peace" after a decade of constant sectarian strife in Northern Ireland.