Blasting onto the scene, recently formed Legendary Pictures is putting up no less than half the production budget for Warner Bros. Pictures’ “Superman Returns” — as well as having footed half the bill of “Batman Begins.”

Legendary, run by financier Thomas Tull and backed by private equity, also will be Warners’ 50-50 co-financing and production partner on M. Night Shyamalan’s “Lady in the Water” and animated family pic “The Ant Bully,” both of which are set for release next summer, as is “Superman.”

Pact between the film studio and Legendary comes at a critical time for the larger Warner Bros. Entertainment, which is looking to trim costs next year and institute possible layoffs in anticipation of a revenue slowdown, particularly on the DVD side. Other divisions of parent conglom Time Warner also are completing aggressive budget reviews, including HBO.

By partnering on a big-ticket item like “Superman” and spreading the risk around, Warner Bros. Pictures can display fiscal responsibility. The high-profile film, directed by Bryan Singer, is still under way shooting in Australia for another few weeks, having begun lensing in the spring.

Sources on the production suggest that the film’s budget is already north of the $208 million being spent on Universal’s “King Kong,” although insiders say the price tag is actually around $175-180 million, factoring in the substantial tax incentives offered in Australia.

The Legendary deal also continues Warner Bros. Pictures’ track record of aggressively going after co-financing partners, such as Village Roadshow.

Linked to big pix

For its part, Legendary and its non-Hollywood investors get immediate cache by attaching themselves to blockbusters and A-list directors. Legendary and Warners will split all revenue streams equally after the studio recoups costs. Warners will handle worldwide distribution.

“One of the central pillars of our philosophy is to back the very best filmmakers, and to be part of projects that are part of our cultural fabric,” Tull said.

Tull said he didn’t mind that Legendary wasn’t able to have a producing credit on “Batman” when the film hit the theaters. Legendary does have a credit on the DVD, which was released earlier this month. Film has grossed more than $200 million at the domestic box office, and $370 million worldwide.

When Warners and Tull announced their pact in late June, all they said was that Legendary planned to invest $500 million in 25 pics over the next five years, suggesting Legendary might attach itself to a series of smaller projects.

Revelation that Legendary is co-producing such tentpole pics as “Superman” and “Batman” suggests that the frosh production and financing company is confident the pool of money will grow to be much more than $500 million as returns are reinvested, explaining why Legendary insists it still will have enough money to fund the full, 25-pic slate.

Not a ‘fund’

Tull, who most recently ran media and entertainment holding company the Convex Group, said it’s wrong for people to think of the $500 million as a “fund.” Rather, Legendary is an operating company. Tull continues to split his time between Atlanta and Hollywood, but intends to relocate to Los Angeles.

Neither Warners nor Legendary would comment on specifics of their deal, citing strict non-disclosure rules.

“The way we approach it is very simple,” Tull said. “We each put up half the money. We each work to produce the film. After the studio recoups costs, our nickel sits next to their nickel, and we all revenue streams.”

Some studios, of course, have been accused in the past of using “Hollywood accounting” practices that allow them to keep a large part of the pie before allocating any money to its financing partners.

‘Financially sophisticated’

“There are some different aspects to this deal that I can’t talk about,” Tull said. “The investor group we have includes some of the most financially sophisticated people around. If these folks came in and financed our company, it’s because they were very comfortable that the deal allowed our interests and Warners’ to be closely aligned.”

Another exec involved with the partnership said that the deal provides “a very fair allocation.”

Traditionally, studios minimize risk by giving financing partners overseas rights.

Unlike other private equity fund deals, such as the $230 million fund at Paramount, Legendary is an active investor, meaning it considers itself a full producing partner, involved in all stages of the process, including budgeting, casting, greenlighting, marketing and merchandising.

Legendary, with offices on the Warner lot, also plans to develop a number of film projects internally.

Warners and Legendary have not yet said what their other co-productions will be, outside of the four just announced.

“Legendary’s enthusiasm for our filmmaking choices and their spirit of collaboration promise to be the cornerstone of a great relationship going forward,” Warner Bros. Entertainment prexy-chief operating officer Alan Horn said.

Investors in Tull’s company include ABRY Partners, AIG Direct Investments, Banc of America Capital Investors, Columbia Capital, Falcon Investment Advisors and M/C Venture Partners. San Francisco-based investment banking firm Perseus acted as financial adviser to Legendary in the transaction with Warners.