FACTBOX: Kennedy's death raises successor speculation

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

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

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.

The governor said on Wednesday that he supports the proposal and would sign it into law if it is approved by the state legislature, saying the prospect of an interim appointment was "eminently reasonable."

"And I think that Massachusetts needs two voices in the United States Senate, especially at a time of momentous change like this," Patrick said on CNN.

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.

A recent poll showed state voters in favor of Kennedy's suggested plan.

Possible Democratic successors include:

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

- Joseph Kennedy, a former member of the U.S. House of Representatives and son of the late Robert F. Kennedy. He runs an organization providing low-cost oil to the poor.

- Former Massachusetts Governor Michael Dukakis, who lost the 1988 presidential election.

- Former U.S. Labor Secretary Robert Reich.

- U.S. Representative Ed Markey.

- U.S. Representative Stephen Lynch.

- U.S. Representative Mike Capuano.

- U.S. Representative William Delahunt.

- Former U.S. Representative Marty Meehan, now a university chancellor.

- Massachusetts Attorney General Martha Coakley.

Possible Republican successors include:

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

- Former Massachusetts Lieutenant Governor Kerry Healey.

- Michael Sullivan, former U.S. Attorney for the District of Massachusetts.

- Andrew Card, former White House chief of staff.

(Reporting by Ellen Wulfhorst in New York and Svea Herbst-Bayliss in Boston; Editing by Stacey Joyce and Paul Simao)