Utah's only uncommitted Democratic superdelegate, Rep. Jim Matheson, announced Thursday he'll support Barack Obama, his party's presumptive presidential nominee.

"Now that the primary season has come to an end and Sen. Obama and Sen. Clinton have been given the time they deserve to bring the party together, I will support the nominee of my party, Barack Obama," Matheson said in a statement.

The only Democrat in Utah's congressional delegation, Matheson had steadfastly refused to back a candidate throughout the primary process. He maintained that neutral position even as the race for the Democratic nomination dragged on months longer than anticipated.

Now, five of Utah's six superdelegates have publicly backed Obama. Helen Langan, the party's national committeewoman for Utah and a spokeswoman for Salt Lake Mayor Ralph Becker, said earlier in the week she wasn't ready to make the switch to Obama.

Langan's boss, Salt Lake City communications director Karen Hale, moved her superdelegate support from Clinton to Obama after Tuesday's elections gave Obama enough votes to secure the party's nomination.

Hale, a former Utah state senator, said it was "time to move on and celebrate our nominee and unite the Democratic Party."

Utah Democratic Party Chairman Wayne Holland told the Deseret News on Tuesday that he believed all the the state's superdelegates would be behind Obama by the end of the week.

Holland had endorsed Obama in April, and named Obama supporter Kristi Cumming a superdelegate at last month's state party convention. Former Utah congressman Bill Orton, the party's national committeeman for Utah, had already backed Obama.

Unlike the party's regular delegates, so-called "superdelegates" are not bound by the results of a state's primary or caucus vote. That's made the party leaders and elected officials serving as superdelegates a key part of this year's primary process.

Clinton is expected to formally announce Saturday she is ending her campaign to become the nation's first female president. She lost to Obama in Utah's Feb. 5 presidential primary.

E-mail: [email protected]; [email protected]