However, his ascent would dismay many Pakistanis, who view him as a symbol of the sleaze that tainted the country's last experiment with civilian rule in the 1990s. He won the nickname "Mr. 10 Percent" for alleged corruption during his wife's turns as prime minister.
And, with the governing coalition that drove Musharraf to resign this week now teetering on the verge of collapse, Zardari's nomination is not certain. He is engaged in intense political horse-trading with the leader of the other key party, former prime minister Nawaz Sharif, who was a bitter rival of Bhutto.
Sharif had no immediate reaction to Zardari's nomination, but his party has been threatening to bolt from the coalition in a struggle over power.
Many citizens, as well as Pakistan's Western backers, are urging the parties to resolve political issues and turn their attention to runaway inflation, slowing economic growth and inexorably rising violence by Islamic militants entrenched along the border with Afghanistan.
That need was rammed home Thursday by twin Taliban suicide bombings that killed 67 people at the country's biggest weapons manufacturing complex, just 22 miles from the capital, Islamabad. On Friday, security forces killed 16 militants, including two suspected suicide bombers, in a clash in the restive frontier in the northwest, officials said.
On Saturday, a suicide car bombing at a police station in northwestern Pakistan killed at least six officers, security officials said. Taliban militants claimed responsibility for the attack.
After seeking to tame militant groups in peace negotiations, the government has been entangled in recent weeks in increasing fighting with hard-line Islamic movements along the border. Militant violence began intensifying after Musharraf ordered soldiers to seize a radical mosque in Islamabad during a bloody battle in July 2007.
According to Associated Press reporting, at least 110 militant attacks have been launched on government, military or police targets since the mosque siege and about 20 attacks have targeted civilians. At least 60 of all those attacks were suicide bombings
The total violence since July 2007, which includes some fighting not initiated by militants, has resulted in the deaths of at least 350 soldiers, 120 police, 470 civilians and 1,000 militants, based on AP reporting.
The 52-year-old Zardari did not immediately accept his party's nomination, but he had done nothing to tamp down the recent chorus from supporters calling for him to take a post that retains many of the powers accumulated during Musharraf's nine-year rule.
"If the major political party believes that he is the most talented person, then he is the most eligible person for this post," said Nabeel Gabol of Zardari's Pakistan People's Party, which gave the leader unanimous support at a meeting Friday.
Party spokeswoman Sherry Rehman said Zardari promised to announce whether to accept the nomination within 24 hours.
"Now it depends on him whether he himself becomes (president) or nominates someone else," Gabol said.
A presidency for Zardari - or a figure under his control - would cap an extraordinary transformation of Pakistani politics that has removed both of Washington's most likely allies from the scene.
Zardari only returned to Pakistan from years in exile after his wife was assassinated in a gun-and-bomb attack last December.
Bhutto, a liberal who courted Western governments and pledged a tough line against Islamic militants, had come back two months before under a U.S.-encouraged deal with Musharraf expected to see them share power after February parliamentary elections.
Musharraf, who gave up his dual post of army chief in November to rule as a civilian president, had by then issued a controversial order quashing corruption charges against Bhutto and her husband.
Zardari has been widely known as Mr. 10 Percent since allegations were raised that he pocketed kickbacks on government contracts during Bhutto's two premierships. He denied the charges, calling them fabrications by political opponents, and he was never convicted.