WILMINGTON, Del. — Edward "Ted" Kaufman, a former aide to Sen. Joe Biden, was named yesterday by Delaware Gov. Ruth Ann Minner to fill the U.S. Senate seat Biden is leaving for the vice presidency.

Kaufman, co-chair of Biden's transition team and an Obama-Biden transition project advisory board member, plans to serve until the 2010 election, when a new senator will be voted in. He said he is comfortable with stepping down after two years in office.

"I don't think Delaware's appointed senator should spend the next two years running for office," Kaufman said. "I will do this job to the fullest of my ability, and spend my days focused on one thing and one thing only: serving Delaware."

Speculation on Biden's successor had centered in recent weeks on his son, Attorney General Beau Biden. But last week the younger Biden announced that he plans to fulfill his National Guard duties and wouldn't accept an appointment to his father's Senate seat.

Beau Biden is a prosecutor for the 261st Signal Brigade, which left for Iraq last week. The unit is due back next September, in time for Biden to run for election to his father's Senate seat.

Just before announcing Kaufman as the appointee, Minner acknowledged speculation about the younger Biden and said she would have strongly considered him.

"The fact that Beau Biden is committed to fulfilling his obligation and not seeking appointment to this office tells us everything we need to know about his character," she said. "Should Beau choose to run for this office in 2010, he will — as will whoever runs — have to earn on his own the trust of the people of Delaware."

Minner said she thinks Kaufman is the best qualified candidate and that she also looked for an appointee whose political views are close to Joe Biden's.

Kaufman's experience in Washington will differ from Biden's in one respect: He does plan to spend time in Delaware, but he and his wife will get a home in Washington — unlike Biden, who commuted on Amtrak between Washington and Wilmington.

In mid-January, Joe Biden will step down as a senator and Kaufman will be sworn in, Kaufman said.

Kaufman held a senior position in all of Biden's federal campaigns.

He served on Biden's Senate staff from 1973 to 1994, including 19 years as chief of staff.

He is a senior lecturing fellow at Duke University and has served by presidential appointment since 1995 as a charter member of the Broadcasting Board of Governors. He also heads a political and management consulting firm based in Wilmington, Del., and previously worked for the DuPont Co.