Egypt's President Hosni Mubarak looked likely to step aside on Thursday after the military high command took control of the nation in what some called a military coup after two weeks of unprecedented protests.

Al Arabiya television, citing what it called trusted sources minutes before Mubarak was due to address the nation, said the 82-year-old leader would say he would transfer powers to his vice president, though it was unclear just how this would happen.

Al Arabiya quoted Mubarak as saying that he could lift emergency laws which were implemented when he took over the presidency after Anwar Sadat was assassinated by Islamist soldiers from his army and which have been in place ever since.

Convinced about the honest intentions of young protesters, Mubarak was also said to be set to repeat that he would not run for another term as president in September elections.

Anything less than quitting could provoke a powerful reaction from the street where the core of protesters want his immediate resignation and reject any political maneuvering that allows him to stay on in some capacity, perhaps as a figurehead.

The armed forces, issuing what they labeled "Communique No.1", announced earlier they were moving to preserve the nation and the aspirations of the people. The Higher Army Council met to try to calm an earthquake of unrest which has shocked the Middle East.

News that Mubarak may hand over power, or be unseated, in this key American ally in the Middle East had provoked loud and emotional cheers in Cairo's Tahrir Square, the focal point for pro-democracy demonstrations. But some in the crowd were quick to protest they did not want military rule.

Mubarak, a former air force commander, was not present at the council meeting. He was to address Egyptians on television.

His information minister, contradicting a host of other sources, said Mubarak would "definitely not ... step down". But others fully expected him to step aside.

Ahead of the address, hundreds of thousands flocked to the square and the surrounding streets with some organizers saying this had been the biggest turnout yet to celebrate their role in modern Egyptian history. Some danced, others played drums.

"The fact that the army met without Mubarak who is the head of the armed forces means that the military has taken over power and I expect this to be announced shortly in Mubarak's televised speech," Nabil Abdel Fattah, at the Al Ahram Center for Political and Strategic Studies, said.

The president has been buffeted by widespread protests that began on January 25 in an unprecedented display of frustration.

Major General Hassan Roweny told tens of thousands of protesters in Tahrir, or Liberation, Square: "Everything you want will be realized."

People chanted: "The people demand the fall of the regime, The regime has fallen".

Others sang: "Civilian, civilian. We don't want it military" -- a call for a freely elected civilian government. It remains to be seen how far the armed forces, which have provided Egypt's post-colonial rulers for six decades, are ready to accept that.

State television showed footage of Mubarak, sitting behind his desk in silence, in a meeting with Vice President Omar Suleiman. The station said they met on Thursday, although that was unclear from the footage. Suleiman, a former intelligence chief, had also not been present at the army council.

Al Arabiya television said the generals planned to support a handover of effective power to Suleiman, a 74-year-old former intelligence chief who has long had the goodwill of Washington and Israel. The military would take action, the broadcaster said citing unspecified sources, if protesters rejected that plan.

Mubarak would announce constitutional procedures before handing over powers, Al Arabiya said.

ORDERLY TRANSFER URGED

Washington's approach to the turmoil in the most populous Arab nation has been based from the start on Egypt's strategic importance -- as a rare Arab state no longer hostile to Israel, as the guardian of the Suez canal linking Europe and Asia and as a major force against militant Islam in the Middle East.

President Barack Obama, hailing history unfolding, said the United States would support an "orderly and genuine transition to democracy" -- Washington would be publicly uncomfortable if the army held on to power, and also does not want Islamist rule.

Asked if Mubarak would step down, an Egyptian official told Reuters: "Most probably".

Mubarak has refused to step down until September polls, saying this could lead to chaos in Egypt. He has vowed not to go into exile. "This is my country ... and I will die on its soil."

On Tahrir Square, General Roweny urged the crowds to sing the national anthem and keep Egypt safe. U.S.-built Abrams tanks and other armored vehicles stood by.

For many, a key question is whether Suleiman might take over effective control from Mubarak -- who might stay on in a figurehead role -- or whether serving officers in the armed forces would move in instead, possibly declaring martial law.

Suleiman, promoted to be Mubarak's deputy less than two weeks ago, is not widely popular. But a key goal for many at the protests has been for changes to laws to ensure fair elections.

Anthony Skinner of the Maplecroft political risk consultancy said: "In the best case scenario, Suleiman would take over and there would be an accelerated transition to democracy. In a worst-case scenario, this turns into effectively a military coup and the military prove not keen on a transition to democracy."

Analyst Michael Hanna from the Century Foundation said on his Twitter feed: "Will people be satisfied under military rule?

"This could create splits among the opposition, and that is probably what the army is hoping for,"

Egypt's sprawling armed forces -- the world's 10th biggest and more than 468,000-strong -- have been at the heart of power since army officers overthrew the British-backed king in 1952.

The army quelled bread riots in Egypt in 1977 and halted a rampage by policemen over pay in 1986, but the scale of the past week's uprising across the country dwarfs those events.

"NILE REVOLUTION"

The protest was partly inspired by the example of Tunisia, where street protesters toppled the president on January 14.

Hundreds of thousands of people have taken to the streets to demand that Mubarak quit and clashes between protesters and security forces have killed at least 300 people.

Mubarak has clung on to power with his promise to step down in September. But that was not enough to end an uprising many now are calling the "Nile Revolution".

Mubarak, who has ruled under emergency laws since he took over when Anwar Sadat was assassinated by Islamist soldiers, also said his son would not stand for election, appointed a vice president for the first time and promised reforms.

"He is going down!" Zeina Hassan said on Facebook.

"We want a civilian state, civilian state, civilian state!" Doaa Abdelaal said on Twitter, an Internet service that many see as a vital catalyst for the protests in Tunisia and Egypt that have electrified oppressed populations across the Arab world.

"The army is worried that tomorrow on Friday the people will overpower state buildings and the army will not be able to fire back," Anees said. "The army now is pressuring Mubarak to resolve the situation."

Organizers had promised another major push on the streets on Friday when protesters planned to move on the state broadcasting building in "The Day of Martyrs" dedicated to the dead.

Washington pressured Mubarak to speed up the pace of reform but stopped short of demanding the resignation of the president of the country, which has a 1979 peace treaty with Israel and an army which receives about $1.3 billion in U.S. aid a year.