FACTBOX: Kennedy's death raises successor speculation

(Reuters) - The death of Sen. Edward Kennedy leaves vacant the U.S. Senate seat he held for nearly five decades and that Democrats will be anxious to fill.

Under state law, Massachusetts Gov. Deval Patrick may not select a successor but must call a special election between 145 and 160 days after the seat comes open.

Before his death, Kennedy asked that the law be changed so an interim senator could be appointed. The ailing statesman said in a letter to Patrick, a Democrat, that the state could not afford to be without a senator for five months.

Under Kennedy's proposal, anyone selected for the interim seat would not be allowed to run in the special election.

Some experts think the state Legislature is not anxious to change the law. Others say they fear Patrick, who is unpopular with voters, may use the appointment to further his own ends.

Kennedy was a powerful voice and a recent poll showed state voters in favor of his suggested plan. The governor supports the plan, as does the head of the state Senate, according to local media.

Possible Democratic successors include:

- Victoria Kennedy, the senator's widow, although aides have told the media she is not interested in the position

- former Rep. Joseph Kennedy, son of Robert F. Kennedy who runs an organization providing low-cost oil to the poor

- former Massachusetts Gov. Michael Dukakis, who ran unsuccessfully for U.S. president in 1988

- former U.S. Labor Secretary Robert Reich

- Rep. Ed Markey of Boston's northern suburbs

- Rep. Steve Lynch of Boston and its southern suburbs

- Rep. Mike Capuano of Boston and Cambridge

- Rep. William Delahunt of the south shore, Cape Cod

- former Rep. Marty Meehan, now a university chancellor

- Attorney General Martha Coakley, the state's first female attorney general

Possible Republican successors include:

- Jeff Beatty, who lost a U.S. Senate bid in 2008.

- former Massachusetts Lt. Gov. Kerry Healey.

- former Massachusetts U.S. Attorney Michael Sullivan.

- former White House chief of staff Andrew Card.