The deal protects about 90 percent of the 165-year-old ranch, and will allow the company to proceed with three development projects in the remaining lands without opposition from environmental organizations including Sierra Club and the Natural Resources Defense Council.

Because of the land's size and proximity to Los Angeles, it had been sought after by developers. Conservationists, however, prize the land because of its biological diversity. Rare plant and animal species, including the California condor, are found on the property.

"Environmental activists and businesses must sit down and work out their differences in the best interest of California," Republican Gov. Arnold Schwarzenegger said of the agreement. "They have done that remarkably well here at Tejon Ranch."

At least one environmental group opposed the deal, saying Tejon Ranch's planned developments would destroy the habitat for the endangered California condor.

"On paper the deal sounds good, but a close examination shows that very little is gained biologically and far too much is sacrificed," Peter Galvin, conservation director at the Centre for Biological Diversity, said in a statement.