A convicted Irish Republican Army terrorist on hunger strike in the Maze Prison in Northern Ireland won a special election today for a vacant seat in the British Parliament from a religiously divided and violence-plagued Ulster constituency on the border with Ireland.

Bobby Sands, 27, a Roman Catholic serving a 14-year prison sentence who has been a leader of IRA convicts demanding political prisoner status, won by 1,446 votes over a prominent moderate Protestant politician, Harry West, 67, former leader of the Ulster Unionist Party.

Sands cannot take his seat in the House of Commons because he is to remain in prison for up to 10 more years if he does not die from his 41-day-old hunger strike. But his election is seen here as a propaganda victory for the IRA after having failed with previous hunger strikes and other protests to gain political status for its Maze prisoners or much international support for its campaign.

"This result has finally proved through the ballot box how deep the support is for the Republican prisoners," contended Danny Morrison, spokesman for the political prisoner campaign in Belfast.

Morrison said Sands does not plan either to resign the parliamentary seat or give up his hunger strike if political-prisoner status cannot be won. "The hunger strike will take its course," according to Morrison.

British officials said the status of Sands and other IRA convicts in the Maze Prison will not be changed by the election result.

This posed a problem for Parliament. The Conservative leader of the House of Commons, Francis Pym, is expected to consult with other parties next week on whether to try to expel Sands so another election can be held.

With an 87 percent turnout, the vote apparently divided along religious lines in the constituency comprising Ulster's Fermanagh and southern Tyrone counties, whose bucolic landscape has frequently been the scene of sectarian killings along the border. Its hidden danger is symbolized by "the Fermanagh widows," a group of 60 Protestant women whose husbands have been murdered in the past decade, mostly by IRA gunmen on hit-and-run strikes from enclaves in Ireland.

Catholics have about a 5,000-vote majority in the constituency, but today's count of the election held yesterday showed that nearly 3,300 voters voided their ballots. They are believed to be mostly Catholics who felt they needed to be seen going to the polls but who did not want to vote for a convicted terrorist.

Several other Catholic candidates dropped out when Sands' supporters, campaigners for political prisoner status for the hundreds of IRA convicts in Maze Prison, entered him in the race.

Bernadette Devlin McAliskey, the veteran Catholic civil rights activist seriously wounded recently by Protestant terrorists, quit as a candidate to campaign for Sands, despite being slowed by her wounds and the need to use a cane.

The moderate Catholic Social Democratic and Labor Party withdrew its candidate because party officials thought Sands would be opposed by Noel Maguire, brother of the independent Catholic incumbent, Frank Maguire, a pub owner and former IRA member who died in office after appearing in Parliament only a handful of times since first being elected in 1974. But then Maguire withdrew under obvious IRA pressure.

Sands has spent all but six months of the last nine years in prison on two convictions of illegal possession of guns. He has served four years of his current sentence after last being arrested near the scene of a gunfight in which two men were wounded.