NEW YORK — John Malone’s Liberty Media Corp. said Monday it will spin off Discovery Networks by the end of June, marking the first of several media breakups that are reversing the synergy-driven mantra of consolidation.

Liberty trumpeted the strength of Discovery as it reported earnings for the last quarter, which saw the company return to a profit on the strength of doc-centric Discovery and home shopping channel QVC. Revenues also were up.

But Starz Entertainment Group, plagued by a hefty jump in programming costs, proved a drag on Liberty’s bottom line, offsetting growth elsewhere and even its own subscriber gains.

Liberty took the unusual step of reporting earnings without holding a conference call for Wall Streeters, saying instead that analysts would be briefed on the quarterly results during an investors meeting Thursday in Gotham.

Neither earnings nor the spinoff will be the only hot topic — Malone and Rupert Murdoch’s News Corp. have yet to ink a deal that would unwind Liberty’s sizable voting stake in News Corp.

No deal yet

Insiders say there is still no definitive deal, but that Murdoch remains eager to regain the voting power now enjoyed by Malone.

According to docs filed Monday with the Securities & Exchange Commission, Liberty Media recorded a profit of $254 million in the last quarter, compared with a net loss of $10 million in the first quarter of 2004.

Revenues clocked in at $1.99 billion, up from $1.75 billion.

Starz saw operating income, or profit, decline 32%, due to increased programming expenses, which jumped from $127 million in the first quarter of 2004 to $165 million last quarter. Liberty owns 100% of the Starz pay channel group, which includes Starz, Encore and Thematic Multiplex.

Revs rise

Results weren’t all gloom and doom for Starz, which saw revenues increase 9% to $254 million on the addition of 19.5 million subscribers.

Revenue at QVC rose 14% to $1.46 billion from $1.28 billion, reflecting higher revenue from both U.S. and international operations. Profit increased to $200 million from $153 million. Liberty owns 98.7% of QVC.

Discovery’s revenues jumped 14% to $601 million from $527 million. Profit rose 8% to $97 million from $78 million a year ago. Liberty owns 50% of the Discovery empire.

Discovery’s U.S. networks saw a 14% jump in subscribers, while revenue from international channels jumped 25% on affiliate and advertising gains.

Liberty’s board has approved a resolution authorizing the spinoff of a newly formed subsidiary, Discovery Holdings Co.

Assets will include Liberty’s stake in Discovery and its 100% stake in post-production company Ascent Media Group.

Liberty shares rose 10¢ to close at $10.50 in trading Monday.