Ailing columnist Robert Novak retires

CHICAGO (Reuters) - Political columnist Robert Novak, who was diagnosed with a brain tumor a week ago, said on Monday his prognosis was "dire" and announced his immediate retirement.

"The details are being worked out with the doctors this week, but the tentative plan is for radiation and chemotherapy," the 77-year-old writer said on the Web site of the Chicago Sun-Times, the newspaper that is home to his column.

In his most famous column in July 2003, Novak caused a stir when he blew the cover of a CIA officer, Valerie Plame, whose husband Joseph Wilson had criticized the Iraq war.

An investigation into who leaked Plame's name later resulted in Lewis "Scooter" Libby, a former top aide to Vice President Dick Cheney, being convicted of lying and obstructing the probe.

Novak's brain tumor diagnosis was made on July 27 after he fell ill at a family gathering in Massachusetts and was taken to Brigham and Women's Hospital in Boston for treatment.

At the time, Novak said through the Sun-Times that he hoped to return to work.

Novak's byline has appeared since 1963 when he and Rowland Evans launched their popular syndicated column that focused on Washington and politics. The pair added a televised version a few years later that evolved into "Evans & Novak," a mainstay of the fledgling CNN network. Evans died in 2001.

The conservative Novak frequently appeared on Sunday morning network television talk shows and engaged in heated debates on CNN's "Crossfire" and other shows until leaving CNN in December 2005. In August of that year he cursed on air and stormed off the set during an argument with Democratic analyst James Carville.

Last month Novak hit a pedestrian on a Washington street with his car but did not stop immediately and later said he was unaware he had hit the man.

(Reporting by Andrew Stern; Editing by David Wiessler)