Slate may start business news Web site -- source

NEW YORK, Oct 31 (Reuters) - Slate, the online news and opinion magazine owned by The Washington Post Co (WPO.N: Quote, Profile, Research, Stock Buzz), may launch a business news and opinion Web site, according to a source familiar with the matter.

The site would be the latest in the growing ranks of business news outlets, joining other start-ups such as Conde Nast Portfolio, at a time when many U.S. magazines and newspapers are retrenching amid a prolonged advertising decline and falling circulation.

Cliff Sloan, Slate's publisher, declined to comment on the Web site's plans.

The New York Observer reported on Wednesday that the site is awaiting final authorization from Post Co executives and that it could go live as early as next summer.

Slate was launched in 1996 by Michael Kinsley, a former New Republic magazine editor and former host of CNN's Crossfire television program, as well as former editorial page editor of the Los Angeles Times.

Run by Microsoft Corp for several years, Slate features a large stable of opinion writing on politics and culture.

Its editor is Jacob Weisberg, a former writer for Newsweek magazine, also owned by The Washington Post Co, and its staff includes journalism critic Jack Shafer and literary editor Meghan O'Rourke, a former editor at The New Yorker magazine. (Reporting by Robert MacMillan)