Romney will file by Wednesday with the Federal Election Commission, the aide said, a registration that will allow the Massachusetts governor to raise and spend money in pursuit of the 2008 GOP nomination.
Romney, like Ford, is from Michigan. Sen. John McCain, R-Ariz., and former New York Mayor Rudy Giuliani, have already taken the same step.
Romney ended a 10-day vacation at his home in Utah on Monday, and he had intended to file his paperwork on Tuesday, the first business day of the new year. But Ford's death on Dec. 26 triggered a mourning period that will close federal offices and the U.S. Postal Service on Tuesday, and the former president will be buried Wednesday in Grand Rapids, Mich.
"We want to be very, very respectful of that," said the Romney aide, who spoke on the condition of anonymity pending the creation of the presidential committee.
Ford's death overshadowedby former Sen. John Edwards of North Carolina, who declared he would seek the Democratic nomination.
While the committee filing will be labeled "exploratory," it will declare Romney as an official presidential candidate and commit him to the same fundraising and reporting rules he will have to follow when, as is expected, he transitions to a formal presidential campaign committee.
A formal announcement is expected sometime later this year, although Romney is planning a major fundraising event in Boston on Jan. 8 to propel his candidacy.
Romney aides believe the governor, the son of George Romney, a 1968 presidential candidate and the former governor of Michigan, can find a following as a youthful alternative to McCain and a more conservative candidate than Giuliani.
If successful, Romney would become the first Mormon elected president.
The 59-year-old is a former venture capitalist who made hundreds of millions of dollars at Bain Capital helping start such companies as Staples, the office-supply giant. He took over the 2002 Olympic Winter Games in Salt Lake City following a bid-rigging scandal that was an embarrassment to Utah, the United States and the International Olympic Committee.
In 2002, he returned to Massachusetts and won a four-year term as governor, his first and only stint in elective office. He unsuccessfully challenged Sen. Edward M. Kennedy, D-Mass., for the U.S. Senate in 1994.
At 5 p.m. Wednesday, Romney will take the "lone walk" down the 31 steps of the Massachusetts Statehouse, a ceremonial departure reserved for presidents, heads of state and departing governors. On Thursday, Democrat Deval Patrick will be sworn in, the first black governor in the state's history and only the second elected in the nation since Reconstruction.
Romney will not attend the ceremony, instead settling into his new campaign headquarters in the city's North End. Aides began moving into the building on Monday, another sign of the impending campaign.
The governor plans to base his campaign out of Massachusetts primarily for logistical reasons, rather than Michigan, his birth state and host to a key early presidential primary, or Utah, a power base in the politically important Mountain West.
Aides say the governor relishes returning to his wife, Ann, and his Belmont home after a stretch of campaign travel. Basing the campaign in Boston also allows him easy access to political consultants in Washington and financial backers in New York.
In addition, it will allow him easier access to New Hampshire, which holds the first presidential primary, and will allow him to stay either in Massachusetts or a second vacation home in the Granite State.