Ta-Ta, UPN. So Long, WB. Hello, The CW.

UPN's affiliation deal with News Corp. is set to expire in August; ditto WB's affiliation deal with Tribune. That became a subject of conversation between Meyer and Moonves, who goes way back with Meyer, having formerly been head of WB Television, developing hit series like "ER" and "Friends."

"We were having dinner one night around Thanksgiving and looked at each other and realized that at that moment in time we were both being pushed by affiliate groups to make long-range commitments . . . and if we were going to find a way to do this together we had to do it now or probably be separated for many years to come," Meyer said.

"We both felt it made sense . . . and went from there. We were of unified purpose."

Yesterday they said that in spite of the costs involved in launching it, they expected The CW to be profitable its first season.

They would not discuss how many people would be laid off as a result of the merger.

In Washington, Tribune-owned WBDC, currently home to the WB network, will become a CW affiliate; News Corp.-owned UPN station WDCA will not.

Yesterday, WBDC General Manager Eric Meyrowitz was doing the happy dance, telling The Post's John Maynard he is "charged up" about the news because "it gives us a better platform to serve the market."

WDCA General Manager Duffy Dyer did not return multiple calls left at his office yesterday.