By Noah Browning and Shadia Nasralla

CAIRO, July 14 (Reuters) - Egypt's interim prime minister filled senior posts on Sunday in a cabinet that will lead the country under an army-backed "road map" to restore civilian rule following overthrow of elected President Mohamed Mursi.

Hazem el-Beblawi, a 76-year-old liberal economist appointed interim prime minister last week, is tapping technocrats and liberals for an administration to govern under a temporary constitution until parliamentary elections in about six months.

He named another liberal economist, Ahmed Galal, who has a doctorate from Boston University, as finance minister. His job will be to start repairing the state finances and rescue an economy wrecked by two and a half years of political turmoil.

A former ambassador to the United States, Nabil Fahmy, accepted the post of foreign minister, a sign of the importance the government places in its relationship with the superpower that provides $1.3 billion a year in military aid.

Mohamed ElBaradei, a former senior U.N. diplomat, was sworn in as vice president, a job he was offered last week.

Government officials had earlier said the finance job would be offered to Hani Kadry, an official who oversaw Cairo's loan negotiations with the International Monetary Fund. It was not immediately clear why Kadry did not end up in the job.

Sunday marks a week without serious street violence. In the day's after Mursi's fall, clashes between the army, his Islamist supporters and Mursi's opponents killed more than 90 people.

In a speech to a hall full of military officers on Sunday, the army chief who removed the president, General Abdel Fattah al-Sisi, justified the takeover. He said the president had lost legitimacy because of mass demonstrations against him.

Sisi said he had tried to avert the need for unilateral action by offering Mursi the option of holding a referendum on his rule, but "the response was total rejection". He insisted the political process remained open to all groups - though Mursi's Muslim Brotherhood has shunned dealings with "usurpers".

"Every political force without exception and without exclusion must realise that an opportunity is available for everyone in political life and no ideological movement is prevented from taking part," Sisi said.

MURSI HELD INCOMMUNICADO

Mursi, Egypt's first freely elected president, has been held incommunicado at an undisclosed location since the army removed him from power on July 3, three days after millions marched to demand he resign on the first anniversary of his inauguration.

The authorities have not charged him with a crime but said on Saturday they were investigating complaints against him over spying, inciting violence and wrecking the economy. The public prosecutor said on Sunday that it had ordered the freezing of the assets of 14 Brotherhood and other Islamist leaders.

Charges of inciting violence have already been issued against many of the Brotherhood's top figures, although in most cases police have not followed through with arrests. The Brotherhood says the criminal charges are part of a crackdown against it and the authorities are to blame for the violence.

Senior Brotherhood leader Essam El-Erian said some 240 Mursi supporters, jailed since dozens were shot by troops a week ago, had their detentions extended in a closed hearing inside the prison where they are being held. Lawyers were barred.

"How could there not be a single lawyer for 240 defendants?" he asked. "This constitutes a serious violation of all the principles of the rule of law. Where are the honourable judges in Egypt to challenge these violations that insult their robes?"

Thousands of Mursi's followers have maintained a vigil in a square near a northeast Cairo mosque, vowing in the brutal summer heat not to leave until he is restored. Last week's start of the fasting month of Ramadan has added to the hardship.

"They kidnapped our president. This is against international law. We don't even know where he is," said Nihad, 37, a lawyer, resting in a tent with other women at the vigil. All were holding Korans, except one playing on an iPad.

Tens of thousands took part in marches on Friday, but the demonstrations ended peacefully, to countrywide relief.

"We feel in the last few days there's more stability, more chance for an economic improvement because there hasn't been a lot of violence," said Ahmed Hilmi, 17, as he manned an open-air stall selling juice for people to break their Ramadan fasts.

The Brotherhood has called for more marches on Monday. Mursi's opponents have also called for demonstrations, though their protests are attracting far fewer people now that they have achieved their aim of bringing him down.

DIPLOMATIC CHALLENGE

The overthrow of Mursi has presented a diplomatic challenge for the West, which had promoted democracy in Egypt but was never comfortable with the Muslim Brotherhood in power.

Washington, which had emphasised Mursi's legitimacy and discouraged demonstrations against him in the weeks before he was removed, has since avoided referring to his removal as a coup but called for his release and for an end to detentions. U.S. law requires a halt to aid for countries after coups.

The State Department said Deputy Secretary of State William Burns would meet members of the interim government and other civil and business leaders in Cairo from Sunday to Tuesday.

"In all these meetings, he will underscore U.S. support for the Egyptian people, an end to all violence, and a transition leading to an inclusive, democratically elected civilian government," the U.S. ministry said in a brief statement.

It did not say whether Burns would meet military officials or anyone from the Muslim Brotherhood.

The European Union, in a statement issued on Sunday by its foreign policy chief Catherine Ashton, urged the interim authorities to prevent "politically motivated arrests", as well as the involvement of the Brotherhood in the political process.

The EU, also an aid donor, has not condemned the military outright, though repeated on Sunday its call for rapid elections and said it was following developments "with deep concern".

Arab states, mostly hostile to the Brotherhood, have had fewer reservations. Jordan's foreign minister visited on Sunday in a sign of support. Saudi Arabia, the United Arab Emirates and Kuwait have promised a total of $12 billion in cash, loans and fuel. A Gulf newspaper reported that two ships had been dispatched bringing $200 million worth of donated Kuwaiti oil.

Beblawi's challenge is setting up a government that will appear inclusive without the biggest Islamist party. The Brotherhood has said it will have no dealings whatsoever with a regime it says was imposed on Egypt after a "fascist coup".

The authorities have instead been courting another large Islamist group, the ultra-orthodox Nour Party, sometime Mursi allies who broke with him and accepted the army takeover.

Nour says it has withdrawn from the "road map" because of government violence and is not seeking ministerial posts of its own, but will back technocrats and offer "advice" to Beblawi.

"We are outside of the road map, but not outside the political scene," Nour's deputy leader Bassam Zarqa told Al Jazeera. "If there are names for ministries that we oppose, we want our voice heard: 'This one's good, this one's not.'"

He added that the party was concerned about the shutting of Islamist media outlets by the authorities, as well as the "vast campaign of detentions" of Mursi supporters.

Beblawi himself was selected only after Nour vetoed other candidates for prime minister, including ElBaradei. (Additional reporting by Yasmine Saleh, Maggie Fick, Omar Fahmy, Patrick Werr and Peter Graff in Cairo and Adrian Croft in Brussels; Writing by Peter Graff; Editing by Alastair Macdonald)