But Aljazeera's correspondent in Beirut reported that the opposition felt less than satisfied with the consultations so far since Miqati had failed to meet their demands.
Miqati's appointment on Friday came after his pro-Syrian predecessor Umar Karami resigned twice in six weeks, leaving the country without a government as it confronted its deepest political crisis since the end of the 1975-1990 war.
The US and European Union voiced hope that the naming of Miqati, a wealthy telecommunications businessman and former minister of public works, would ensure that legislative elections are held as planned by the end of May.
US President George Bush issued a stern reminder to Syria, the main power broker in Lebanon for almost three decades, to complete its troop pullout from the country before the elections.
Bush said: "When I say, get out of Lebanon, I mean out of Lebanon with all your troops and all your security services and all the people trying to influence that government. It is in the world's interest that Lebanon be allowed to have free elections, because a free society will help spread the peace."
The EU said it hoped a new cabinet would be formed at an early date. It urged the Lebanese authorities to proceed without delay to free, fair and transparent elections on schedule.
"When I say, get out of Lebanon, I mean out of Lebanon with all your troops and all your security services and all the people trying to influence that government"
Lebanon has been without a government since Karami resigned at the end of February under the weight of huge protests sparked by the assassination of his predecessor Rafiq al-Hariri in a massive Beirut bomb blast.
In the upheaval that followed, the international community succeeded in pushing Syria to promise an end to its 29-year military presence in Lebanon by 30 April, although it remains a powerful political influence.
Miqati, a family friend of Syrian President Bashar al-Asad, met former prime ministers on Saturday and started parliamentary consultations on Monday, facing an end of April deadline to call elections.
"I come with an open hand and an open heart so that we can all cooperate in the interests of Lebanon," the 49-year-old Sunni Muslim said after his selection.
"We are facing a new period, a return to democracy," he said, pledging to be a symbol of moderation and national unity.
"I come with an open hand and an open heart so that we can all cooperate in the interests of Lebanon"
Lebanese Prime Minister
He told top-selling Al-Nahar newspaper he intended to form a "restricted government that could hold elections as soon as possible" and would sack security service chiefs before a UN commission arrives to probe al-Hariri's murder.
Lebanon's opposition, which found a powerful new voice after the killing of al-Hariri, blamed the attack on the pro-Syrian government and its political masters in Damascus and had been demanding the sacking of top security officials.
Miqati was chosen over Damascus protege President Emile Lahud's candidate, outgoing Defence Minister Abd al-Rahim Murad, amid signs of cracks among loyalists allied to Syria.
The opposition, which expects to win the elections and had warned of more mass street protests if a government was not formed soon, decided to back Miqati after he pledged to meet some of their demands and despite his links to Syria.
"The important thing is that he keeps the promises he made," opposition MP Nayla Muawad said.
Bahia al-Hariri (R) has shown her
support for Miqati's appointment
"We have undoubtedly entered the era of the settlement of the crisis. There is a danger of instability ... which prompted us to choose a prime minister who is close to all parties, including the Syrian leadership and Dr Bashar al-Asad."
Al-Hariri's sister, MP Bahia al-Hariri, met Lahud for the first time since her brother's killing to back Miqati's nomination.
"We were facing two things: either to enter a constitutional vacuum or offer a compromise, and this is what the opposition chose," she said.
In further signs of reconciliation, Walid Jumblatt met for the first time in Paris on Friday his former wartime foe, exiled Christian leader Michel Aun.
Aun, who plans to return home next month, told Al-Safir he had agreed with Jumblatt to join the next government.