Following the box office success of "March of the Penguins," The Walt Disney Co. said Monday it launched a new film production unit called Disneynature to produce and distribute documentary films through at least 2012.

The 2005 documentary about penguin families surviving in Antarctica grossed $127 million at the global box office but cost just $3 million to make, said Jean-Francois Camilleri, who helped Disney co-produce the film and will head the new unit as executive vice president.

"First of all it was a great film," Camilleri said. "The fact that it worked shows that people had an appetite for it."

The first film to be released in the U.S. will be "Earth" on Earth Day, April 22, 2009. A separate version of the BBC Worldwide and Greenlight Media production was previously released in France, Japan and Germany and earned a total of $70 million.

"Earth" focuses on a yearlong journey of three mothers — a polar bear, elephant and humpback whale — with their offspring.

The first film released with the Disneynature brand will be "The Crimson Wing: Mystery of the Flamingos." It will premier in France in December, with other release dates yet to be announced.

Disney chief executive Robert Iger said the unit marks a return to the Disney tradition. Among other things, the company made the film series "True-Life Adventures" from 1948 to 1960.

He expects the movies to receive wide release in theaters and create spinoff products that could appear in Disney enterprises on the Internet and in bookstores and theme parks.

The films are expected to create new product lines without straining animation or other studio resources, he said.

"When you create high-quality family entertainment, you can have both success and create shareholder value," he said.

Disney shares rose 13 cents, or 0.4 percent, to close at $31.46.