NEW YORK (AP) _ The PaineWebber conference for media analysts, which gets under way next week, has long been one of the key events in the annual media calendar. But this year, a number of major newspaper companies are defecting to a rival meeting put on by another brokerage, Donaldson, Lufkin & Jenrette.

Many media companies will make presentations at both, including Time Warner Inc., T.V. Guide Inc. and several advertising and cable TV companies. But several others, mainly newspaper publishers, decided to make presentations only at the DLJ meeting, which is being inaugurated this year.

Spokesmen for Dow Jones & Co., The New York Times Co. and Knight Ridder said they chose to attend the new conference because_ as of this summer, when the meetings were being organized _ DLJ had a securities analyst covering their companies while PaineWebber did not. DLJ's newspaper analyst, Bill Drewry, used to work at PaineWebber until last year.

Other companies presenting only at DLJ include Gannett Co., E.W. Scripps Co., McClatchy Co., Central Newspapers Inc. and Journal Register Co. The Washington Post Co. and Tribune Co. will present at both, and Pulitzer Inc. and A.H. Belo Corp. are sticking with PaineWebber.

DLJ has closed its proceedings to reporters, but the PaineWebber meeting, which has been put on for the past 26 years, will remain open to the press.