Rep. Roscoe Bartlett, the lone Republican in the state's congressional delegation, confirmed Monday that he is running for a tenth term in 2010.

Bartlett, also the oldest Marylander in Congress, said through an aide that he wants to keep the seat he first won in 1992.

A formal announcement will come "some time in the future," said spokeswoman Lisa Wright.

Bartlett had already begun raising money for a re-election run. He is considered a heavy favorite to win his largely Republican district, which extends along the Mason-Dixon line from northern Harford and Baltimore counties through all of Western Maryland. Last fall, Barack Obama lost the district badly to John McCain while carrying the rest of the state by roughly two-to-one.

The Frederick congressman confirmed his plans in response to an expected announcement Monday evening by Andrew Duck, a Democrat, that he wants a rematch with Bartlett. In 2006, Duck drew 38 percent of the vote after getting outspent two-to-one by the incumbent.

Duck, a career Army intelligence officer, lost the 2008 Democratic primary by about 4,300 votes to Jennifer Dougherty, a former Frederick mayor. She went on to lose the general election to Bartlett, who received almost 58 percent of the vote.

Bartlett, who turns 83 on Wednesday, had $325,939 in his campaign account as of March 31, the most recent date for which Federal Election Commission data is available.

That's considerably more than he spent in his entire 2008 re-election campaign.

Bartlett's spending last time was unusually modest for an incumbent in a contested race--just over $200,000. His low-budget election victory was a reflection of his popularity in the conservative district and a clear sign that Duck or some other Democrat faces a very steep challenge in trying to unseat him.