Another candidate is announcing a challenge to Mayor Adrian M. Fenty and his $2.5 million war chest: Leo Alexander, a former WRC-TV newscaster, is announcing a mayoral run tonight.

Alexander will join Sulaimon Brown, a former Fenty 2006 volunteer, as Fenty’s only declared competition for the 2010 race.

Alexander was a Channel 4 reporter in the mid-1990s before moving on to communications jobs for the D.C. General Hospital and the D.C. Housing Authority. A Brightwood resident since 1999, Alexander now works in insurance sales and has been active in the Brightwood Civic Association and the D.C. Federation of Civic Associations.

Politically, Alexander is not a widely known quantity and won’t gain the instant credibility and fundraising heft of a Vincent Gray or Kwame Brown or Michael Brown. But in the absence of a challenge from any of those parties, Alexander stands to capture support from the anyone-but-Fenty crowd.

Alexander will be kicking off his run tonight at 7 p.m. at Pier 7 Restaurant at 650 Water St. SW.