Dale Van Atta, who was an irrepressible Deseret News investigative reporter before joining Jack Anderson in 1979 and later becoming his journalistic heir, is leaving Anderson's "Washington Merry Go-Round" staff.

Van Atta has been writing 200 of the columns every year and says he will continue to do 50 - which in just about anybody else's book would be a full-time effort. But his decision essentially will split as of the end of the month two of the best-known journalists ever to blaze across the national scene from Utah as well as the two feistiest.Van Atta and Anderson have been sharing the byline for the nation's most popular political column, which 600 newspapers use.

- IN 1985 ANDERSON, who was then 63, announced that Van Atta "has the imagination and boldness eventually to take of the leadership of the column. He also has the gift for digging out facts that are seemingly inaccessible."

Anderson, who won the Pulitzer Prize for national reporting, noted that Van Atta has been nominated five times for the Pulitzer. Three of the nominations came from the Deseret News, where Van Atta was from 1973 to 1979 a member of the now-defunct Pinpoint investigative team. The latest News nomination was, in the words of the nomination, for his work as the "driving force behind a yearlong series of more than 100 articles on . . . Tooele Army Depot, which sparked a national congressional inquiry."

Anderson was student body president at Granite High School, a kid editor at the weekly Murray Eagle and reported later briefly for the Tribune and the Deseret News. He hitched his career to Drew Pearson's star in Washington in 1947, first as Pearson's legman and then as his associate, taking over on Pearson's death in 1969.

A Time magazine cover story on Anderson in his Pulitzer year of 1972 called him a "supersnooper" in the grand muckraking tradition of American journalism. "A clumsy writer who has yet to put together any memorable combination of words, he has nevertheless emerged in the past dozen weeks as the pre-eminent scourge of Washington."

- WHY WOULD VAN ATTA want to part ways, particularly since he and Anderson are so philosophically in tune (both holding, for instance, that most newspapers are timid and overly deferential to Washington authority)?

Van Atta told the trade magazine Editor and Publisher that his resignation "may have had a bit to do with turning 40 in September." He wants new financial opportunities, observing that columnists make more from TV, speeches and books than from the column itself. (Anderson has always insisted that he takes no money from the column but uses that income entirely to support his staff.)

Van Atta and Anderson speak highly of one another. Anderson says he tried hard to get Van Atta to stay. Van Atta says Anderson has been "outstanding to work with," an appraisal Anderson's associates, if not always the people he writes about, have long expressed.