* Early results show more than 90 pct voted "yes" -state media
* Vote seen paving way for Sisi presidential bid
* Analyst sees popular general running unopposed
* Nine killed, 444 arrested in unrest during vote (Adds foreign ministry comment, analyst)
By Tom Perry and Maggie Fick
CAIRO, Jan 16 (Reuters) - Egypt's new constitution was overwhelmingly approved in a referendum, state media reported on Thursday, an expected victory that nudges army chief General Abdel Fattah al-Sisi ever closer to a bid for the presidency.
The vote advances a transition plan the army-backed government unveiled after deposing Islamist president Mohamed Mursi last July following mass protests against his rule.
The next step is expected to be a presidential election for which Sisi - wildly popular among his supporters - appears the only serious candidate. He has yet to declare he will run.
Some 90 percent of the people who voted approved the constitution, state-run media reported. Al-Ahram, the state's flagship newspaper, said the constitution was approved by an "unprecedented majority", citing early results.
The constitution won wide support among the many Egyptians who backed the army's removal of Mursi. The Muslim Brotherhood had called for a boycott, saying the vote is part of a coup that deposed an elected leader and revived a brutal police state.
Rights groups criticised the detention of seven activists from a moderately Islamist party campaigning for a "no" vote.
In a statement, the foreign ministry said they were arrested on suspicion of law-breaking and all but one of them, held in relation to a past conviction, had been released. It added that there was no ban on campaigning for a "no" vote.
An Interior Ministry official said turnout appeared to be more than 55 percent in the first vote since Mursi's removal.
A decree is expected within days setting the date for presidential and parliamentary elections, Al-Ahram reported. The official result is expected to be announced on Saturday.
Some of the Islamists' opponents pointed to the result as proof of a popular mandate for Mursi's removal. "The Egyptians write the Brotherhood's death certificate," Al-Youm Al-Sabea, a privately owned newspaper, declared on its front page.
The Brotherhood had called for protests during the voting. Nine people were killed on the first day of voting in clashes between its supporters and security forces. The Interior Ministry said 444 people were arrested during the two-day vote.
The authorities, who have billed the transition plan as a path to democracy, have also jailed leading Islamists and, in recent weeks, secular-minded activists, including prominent figures in the 2011 uprising against President Hosni Mubarak.
Mursi and other top Brotherhood politicians are standing trial on charges including inciting violence and conspiring with foreign militant groups against Egypt. Several members of the secular protest movement have also been jailed for breaking a new law that tightly restricts the right to demonstrate.
STOCK MARKET RALLY
The referendum has been seen as a public vote of confidence in Sisi, 59, widely viewed as the most powerful figure in Egypt and by his supporters as the man needed to restore stability.
"I believe this is the most convenient time for Sisi to make an announcement if he has the intention to run," said Mohamed Qadri Said, a retired army general who works at the state's Al-Ahram Centre for Strategic and Political Studies.
"I do not see anyone else running against him. He has done great things to the country and the people like him."
The stock market has rallied to three-year highs this week, driven partly by hopes for more stable government.
But the country has also seen the bloodiest internal strife in its modern history since Mursi's ouster. Bombings, attacks on security forces and bloody street violence occur regularly.
The government declared the Brotherhood a terrorist organisation on Dec. 25. The group, outlawed for most of its 85-year life, says it remains committed to peaceful protest.
The constitution was drafted by a 50-member committee appointed by decree. It deletes controversial Islamist-inspired provisions written into the basic law approved when Mursi was still in office, and strengthens the state bodies that defied him: the army, the police and the judiciary.
At many polling stations, the referendum appeared to be a vote on Sisi himself. Women chanted his name and ululated as they stood in line to vote, while a pro-army song popularized after Mursi's overthrow blared from cars.
The Cairo Institute for Human Rights Studies criticised Egyptian media for "stoking hatred towards the Brotherhood" and contributing to a climate of intimidation.
The Carnegie Endowment for International Peace in Washington warned that international players risked lending legitimacy to a "flawed and undemocratic progress."
While Western states have criticised the crackdown and called for inclusive politics, they have put little pressure on Cairo. Egypt, which controls the Suez Canal, has been a cornerstone of U.S. policy in the Middle East since the 1970s, when it became the first Arab state to make peace with Israel. (Additional reporting by Ali Abdelatti and Sameh Bardisi; Editing by Tom Heneghan)