Finally, Mubarak steps down

* Leave to Cairo for Sharm el-Sheikh with family

* Jubilant people chant "We have brought down the regime"

* Wall St extends gains as Mubarak goes

* Egypt army to suspend parliament, sack cabinet

CAIRO (Reuters) - Egyptian President Hosni Mubarak has stepped down and the vice president has named a military council to run the country's affairs, state television said on Friday after 18 days of mass protests against his rule.

A ruling party official said earlier that Mubarak and his family had left Cairo for the glitzy Red Sea resort of Sharm el-Sheikh where there is a presidential residence. He added that this proved Mubarak had handed powers to deputy Omar Suleiman.

In the morning, Egypt's powerful military gave guarantees that promised democratic reforms would be carried out but angry protesters intensified an uprising against Mubarak by marching on the presidential palace and mobbing the state television hub.

The army's gesture was an effort to defuse an 18-day-old revolt unprecedented in modern Egypt but, in ignoring the key demand of protesters for Mubarak's ouster now, it failed to stop turmoil disrupting the economy and rattling the Middle East.

Mubarak had promised only that he would not stand for re-election in September and that he would preside over reforms until then.

This was not enough for the many hundreds of thousands of mistrustful protesters who rallied in cities across the Arab world's most populous and influential country on Friday, fed up with high unemployment, a corrupt elite and police repression.

The escalating confrontation has raised fears of uncontrolled violence in the most populous Arab nation, a key U.S. ally in an oil-rich region where the chance of chaos spreading to other long stable but repressive states troubles the West.

Hundreds of thousands of Egyptian protesters waved flags, cried, cheered and embraced in celebration on Friday when the resignation of President Hosni Mubarak was announced.

"The people have brought down the regime," chanted the crowds in Tahrir Square.

Another report said Egyptian President Hosni Mubarak and his family have left Cairo for the Red Sea resort of Sharm el-Sheikh, proving he is giving up his presidential powers, a ruling party official said on Friday.

NEW YORK (Reuters) - U.S. stocks briefly extended gains on Friday after news that Egyptian President Hosni Mubarak had stepped down after demonstrations against his rule.

The Dow Jones industrial average <.DJI> gained 33.34 points, or 0.27 percent, to 12,262.63. The Standard & Poor's 500 Index <.SPX> gained 4.62 points, or 0.35 percent, to 1,326.49. The Nasdaq Composite Index gained 7.53 points, or 0.27 percent, to 2,797.98. Egypt's higher military council will sack the cabinet, suspend both houses of parliament and rule with the head of the supreme constitutional court, Al Arabiya television reported on Friday.

The army statement was expected to be delivered later on Friday and followed President Hosni Mubarak's dramatic resignation after 30 years in power.