Disappointing a roomful of supporters chanting "Run, Roland, Run," U.S. Sen. Roland Burris officially announced Friday that he would not seek his Senate seat in the 2010 election.

In a short speech that contained few details, Burris said the expense involved in running for office was a big factor in his decision. He reportedly managed to raise just $845 in the first three months of this year.

"I was called to choose between spending my time raising funds or spending my time raising issues for my state," he said at the Chicago South Loop Hotel on the city's South Side. "The business of the people of Illinois should always come first."

Burris took no questions from reporters after his speech.

The 71-year-old senator plans to serve for the remainder of his term, which expires in January of 2011. Burris said he is proud to be a member of the Senate at a time when President Barack Obama and Vice President Joe Biden are "reinforcing the promise of the American dream" by focusing on issues such as health care, the creation of jobs, the environment and education.

"I look forward to working with (Obama) on these pressing issues of our time," Burris said.

Controversy has swirled around Burris ever since he was appointed to the Senate in December by then-Gov. Rod Blagojevich. Blagojevich made the appointment shortly after federal prosecutors accused him of trying to sell the seat to the highest bidder, but before he was removed from office.

Senate Democratic leaders initially vowed not to seat Burris, but eventually relented when he agreed to give sworn testimony about his appointment to an Illinois panel that was considering impeaching Blagojevich. He told that panel he had talked to only one Blagojevich associate about the Senate post before it was offered, but later acknowledged other conversations. He denied having any discussions of campaign donations, but it turned out federal investigators had recorded him talking to Blagojevich's brother about the possibility of raising money for the governor.

Burris has maintained he did nothing improper to get the seat. A prosecutor who looked into whether Burris should be charged with perjury for his incomplete testimony to the impeachment panel concluded it would be impossible to prove.

Burris did not comment directly on these troubles Friday, though he appeared to refer to them when he said: "Serving in public life is not easy, friends, but it is a noble, rewarding calling."

Though a number of potential candidates for the seat have already emerged, Burris did not offer support to any particular person. He made a point of mentioning, though, that he is the only black senator currently in office, and that it's important for the government to show racial and ethnic balance.

"I believe that diversity and representing all segments of our society is essential to who we are as a nation," he said. "We must have diversity."

• Daily Herald news services contributed to this report.