FACTBOX: Possible Senate successors for Kennedy

(Reuters) - Massachusetts Governor Deval Patrick will make an announcement at 3 p.m./1900 GMT on Monday about a special election to fill the Senate seat left vacant when Democrat Edward Kennedy died of cancer last week.

Kennedy's death deprived Democrats of the 60 votes in the 100-seat Senate needed to overcome Republican procedural blocks to key legislation such as the healthcare reform urged by President Barack Obama.

Under Massachusetts law, once a Senate seat becomes vacant, there is a 145- to 160-day period before a special election is held, opening a potential five-month period when Massachusetts would have only one senator. Before he died, Kennedy had asked for that period to be changed to fill the seat more quickly.

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 Paul Simao and Bill Trott)