BELFAST, Northern Ireland — Northern Ireland's major Protestant and Catholic leaders, sitting side by side for the first time in history, announced a surprise, stunning deal yesterday to forge a power-sharing coalition of long time foes."We all saw something today that people never, ever thought would happen," said British Secretary of State Peter Hain, who expects to hand power on May 8 to a coalition led by the polar opposites of provincial politics: Ian Paisley's Democratic Unionists and Gerry Adams' Sinn Fein.

Paisley, an 80-year-old Protestant evangelist who for decades has sought to thwart compromise with Catholics, sat beside Adams, a reputed Irish Republican Army veteran whom Paisley long denounced as a "man of blood." Throughout the tortuous 14-year course of Northern Ireland's peace process, Paisley had never agreed to negotiate directly with Adams before.

Their agreement, after barely an hour of discussions in the lawmakers' dining hall in Stormont Parliamentary Building in Belfast, called for Sinn Fein and the Democratic Unionists to work directly together on a detailed programme for government.

Britain, in turn, promised to pass emergency legislation today that would extend its deadline for a working power-sharing government from yesterday to May 8. On that date, the Northern Ireland Assembly would elect a 12-member administration with Paisley at its head and Sinn Fein deputy leader Martin McGuinness, rather than Adams, in the number two post.

Paisley and Adams generally looked at their scripts, not each other, as they addressed live television audiences across the United Kingdom and Republic of Ireland. Both agreed they must leave behind Northern Ireland's bitter divisions and forge a unity government, the central goal of the Good Friday peace pact of 1998.

"We must not allow our justified loathing of the horrors and tragedies of the past to become a barrier to creating a better and more stable future for our children," said Paisley, whose party previously boycotted contact with Sinn Fein because of its links to the outlawed Irish Republican Army.

"In looking to that future, we must never forget those who have suffered during the dark period from which we are, please God, now emerging," Paisley said. "We owe it to them to craft the best possible future."

Adams, 58, said yesterday's accord "marks the beginning of a new era of politics on this island."

"The relationships between the people of this island have been marred by centuries of discord, conflict, hurt and tragedy. ... Now there's a new start, with the help of God."

The conflict over Northern Ireland, a corner of the United Kingdom with 1.7 million residents, has claimed more than 3,600 lives since the 1960s — when Adams was an up-and-coming IRA member from Catholic west Belfast, Paisley the province's most infamous opponent of a Catholic civil rights movement.

By the mid-1980s, Paisley campaign posters were picturing him carrying a sledgehammer and vowing to "smash Sinn Fein." That party had begun contesting elections as part of Adams' strategy to end his diplomatic isolation and turn IRA diehards toward politics.

Britain and Ireland have spent 3[1/2] years trying to coax the Democratic Unionists toward Sinn Fein following their triumph in 2003 assembly elections.

The British and Irish prime ministers, Tony Blair and Bertie Ahern, appeared to have forced Monday's breakthrough by declaring March 26 their "unbreakable" deadline: Either the Democratic Unionists would agree to co-operate by that date, or Britain would abolish the assembly — something neither side wanted.

While Monday's deadline was missed, others agreed that the Democratic Unionists' dramatic decision to end their boycott of talks with Sinn Fein was worth it.

"Now at last we have a date certain for the devolution of power and a remarkable coming together of people who have, for very obvious reasons, been strongly opposed in the past," said Blair, who has toiled to conclude the peace process before he steps down from power this summer.

"I am elated that this day has finally come," said former US President Bill Clinton, whose personal interest in Northern Ireland — and his controversial decision to grant Adams a 1994 visa while the IRA was still killing — dramatically spurred peacemaking.

Sinn Fein officials appeared overjoyed to be talking, finally, with their would-be government partners, rather than via the British government or other third-party messengers.

"I never quite thought I would see the day. But it was remarkably easy. Both delegations were quite relaxed," said Sinn Fein lawmaker Conor Murphy, who added that the opening of normal dialogue bode well for the future administration's stability.

Sinn Fein made its own historic turnaround two months ago — opening normal relations with the predominantly Protestant police force. That followed the IRA's landmark 2005 decisions to disarm and formally abandon its 1970-1997 campaign to overthrow Northern Ireland by force.

Power-sharing was the central goal of the US-brokered Good Friday deal. The last, moderate-led coalition collapsed in October 2002 amid chronic arguments between Protestants and Sinn Fein over the future of the IRA, which at the time was refusing to disarm and was accused of gathering intelligence for a potential resumption of violence.

The Democratic Unionists boycotted the negotiations that produced the Good Friday deal because Britain permitted Sinn Fein to participate. The Democratic Unionists did take posts in the power-sharing government of 1999-2002, but refused to attend Cabinet meetings because Sinn Fein ministers were there.