Senator Bob Dole, who is known to be planning to announce his candidacy for President, appeared on "The Late Show With David Letterman" last night and made what he described as an informal announcement of his formal announcement.

Mr. Dole, a Kansas Republican, did not rise to the level of serious newsmaking that Ross Perot did in 1992 when he appeared on "Larry King Live" on CNN to announce his candidacy for President. And it appeared that the Senator was trying to present a softer image for Mr. Letterman's youngish audience.

When Mr. Letterman asked the Senate leader whether he had just announced his candidacy, Mr. Dole replied, "I have not, but I'm going to run."

Mr. Letterman then said, "You're going to run for---- "

"President," Mr. Dole broke in, adding shortly, "I've thought about it and I decided that every country ought to have a president."