MSNBC is axing John Hockenberry's talk show after just six months on the air.

"It's a little bit mystifying," Hockenberry said yesterday, adding that he did not understand "the strategy or lack of same in the MSNBC programming universe." He said a network executive had told him that "we want to move in a different direction" and that "a live show focused on the news cycle doesn't seem to work."

This is the second such cancellation for Hockenberry, an award-winning journalist who will return full time to his role as a "Dateline NBC" correspondent. His weekend show "Edgewise" was dropped by MSNBC two years ago. "Hockenberry" will end within days.

The decision comes as a surprise because MSNBC heavily promoted Hockenberry, particularly during the war in Yugoslavia, when he did his 10 p.m. show live from the Balkans. But it is part of a game of musical chairs as the Microsoft-NBC venture again shuffles its prime-time lineup.

Hockenberry was the replacement last December for Keith Olbermann, who left for Fox Sports after getting fed up with the Monica Lewinsky scandal--and took plenty of MSNBC viewers with him.

"I think we succeeded," Hockenberry said. "We had interesting, better ideas than just a standard talk show. If there's any lesson in cable, it's that there is no six-month trial period. It takes the audience a while to find you."

Ironically, Hockenberry's ratings jumped 22 percent from the first quarter of 1999 to the second, reaching an average of 232,000 households. But from May 17 to July 1, as the Kosovo conflict faded, his numbers dropped 63 percent, compared with a 58 percent decline at CNN and a 38 percent slide at Fox News Channel during the same time period.

MSNBC spokesman Cory Shields would not confirm the canning of Hockenberry, saying only that "we'll be announcing a new prime-time schedule in the next couple of weeks."

That schedule, network sources say, will include a biography program, "Headliners and Legends," to be hosted by Matt Lauer of "Today." It's also likely that Chris Matthews will move his "Hardball" gabfest to MSNBC from CNBC, which is preparing to extend its daytime business programming as the stock market moves toward evening trading hours. Matthews's new contract allows for such a switch.

MSNBC trumpeted the hiring of former White House aide Paul Begala to join Oliver North on "Equal Time," but then bumped the low-rated show from 8 p.m.--where insiders now say it was "plugging a hole"--to the relative Siberia of 6:30.

Was Hockenberry, too, plugging a hole? "John's a great guy," an MSNBC staffer said. "Everyone loves John Hockenberry. He did a fabulous job." But Matthews is a stronger choice, this person said, because he "has a track record at CNBC" and "comes with a ready-made audience."

NBC executives are said to view the reshuffling as a "win-win" situation, since Hockenberry gets to reach 15 million viewers on "Dateline," Matthews moves from one NBC cable outlet to another and neither is lost to the company.

CAPTION: John Hockenberry, puzzled by MSNBC's shuffle.