The Walt Disney Co.’s plans to transform a slice of its bucolic ranch near Santa Clarita into a 21st century production center gained a key approval on Wednesday, as the Los Angeles County regional planning commission gave unanimous approval to the project, with some estimates that it will cost in the hundreds of millions of dollars.

Disney’s plans are to build up to 12 soundstages, offices, bungalows, a commissary and parking on nearly 60 acres of its 846-acre property, called the Golden Oak Ranch, where it has filmed such classics as “Old Yeller” and “The Shaggy Dog” and, more recently, scenes from the “Pirates of the Caribbean” films.

The project will now go before the county Board of Supervisors, with a vote expected in the coming months.

The project faced few objections in comments filed before today’s meeting, except for concerns from the California Native American Heritage Commission that the project site was a “culturally sensitive” area and that care needed to be taken to protect it. At the hearing, some concerns were raised by nearby residents over the project’s impact on traffic and water usage, but others expressed support.

The project also will require the removal of 158 oak trees. Disney plans to plant some 1,600 new oak trees to make up for the loss.

Disney, which unveiled plans for the new lot in 2009, said that it will allow the company to consolidate production in the area to one facility, and to shoot interior and exterior scenes in the same location.

Richard Ballering, VP of production operations for ABC, said it was “really too early to discuss” a construction start because “right now we are simply focused completely on the approval process.” He declined to say whether the project will be built in phases or all at once, saying that the “planning process is still ongoing.”

The company is naming the facilities Disney/ABC Studios at the Ranch, and it says that it will create almost 2,900 jobs and generate about $533 million in annual economic activity throughout the county. But it is also a signal of confidence that the company has that such an investment will be needed in the digital age. Even as studios grapple with changing business models, the growth in production in cable has increased demand for studio space. NBC Universal and Paramount are also in the midst of planning for major upgrades to their facilities in Universal City and Hollywood, respectively.

Disney first shot on the Golden Oak Ranch site in the late 1950s, when it leased space for the “Adventures of Spin & Marty” segments of “The Mickey Mouse Club.” It began acquiring portions of the property in 1959, growing its investment in the years since. The ranch includes rural sets, like a covered bridge, cabins and barns; a residential street; an urban district and even a jungle setting.

Starting in the 1920s, studios began investing in sprawling properties within a 30 mile zone of their headquarters, as a way of saving on the costs of location shooting elsewhere. Walt Disney’s intention in buying up the land was to set aside acreage as suburban sprawl and freeway construction made it more difficult to find natural vistas. Fox and Paramount each owned ranches, but their properties were eventually sold off for use as state and national parkland.

“The entertainment industry is continually evolving,” Ballering said. “This project is about planning for our future and ensuring that we are controlling our destiny.”