Apple Corps Ltd. is like a doting parent when it comes to The Beatles, looking after their interests and promoting their recordings, a writer said Friday, but it also makes sure no one tries to mess with the band's legacy.

The company is in court again this week, fighting Apple Computer Inc. (AAPL) over the iTunes Music Store, the latest battle in a long-running dispute with the U.S. company over the apple logo.

"They regard the Beatles as their four boys — John, Paul, George and Ringo — so Apple Corps looks after their music," Keith Badman, a Beatles expert and author, said Friday.

"You don't get the Beatles' version of 'Penny Lane' being used in a cheap advertisement," Badman said. "They make sure the Beatles' recorded music is not damaged, and that's a good thing."

Apple Corps — set up by the group in 1968 and still owned by Paul McCartney, Ringo Starr and the widows of John Lennon and George Harrison — is an ever-alert watchdog, growling whenever anyone approaches the Beatles' property. It is responsible for approving merchandising and licensing for the group, as well as protecting the company's valuable apple trademark.

In the lawsuit at London's High Court, Apple Corps is seeking to force Apple Computer to drop its logo from the iTunes store and pay unspecified damages. The California-based company has countered by saying a 1991 agreement between the two Apples allows them to distribute entertainment content.

Apple Corps has also battled with EMI Group, which releases the Beatles' recordings under the Apple label, over royalties. It is equally vigilant about protecting its territory in other spheres, filing lawsuits on everything from the Fab Four's images on postage stamps to the stage show "Beatlemania."

Who owns what is a complex issue. While EMI releases the Beatles' albums, the publishing rights to words and music of 251 Beatles songs are owned by Michael Jackson and Sony/ATV Music Publishing.

The company is also instrumental in continuing The Beatles' popularity. It was behind the release of the 2000 hit album "1", which featured hits as diverse as "She Loves You" and "Hey Jude." Sales of that album topped 24 million.

The Beatles set up Apple Corps to be a corporate utopia, said Peter Doggett, the author of several music books, including one about John Lennon.

Founded in the flower-power days, the company was going to behave in a relaxed way where artists could pop into the offices and not be confronted by stuffy men in suits.

"It began as an ideal corporation," Doggett said, "which, in Paul McCartney's words, was supposed to operate in a nice kind of Western communism."

Operating out of offices in a tony central London neighborhood, Apple Corps keeps a low profile — at least on the Internet. Its Web site is just one page, with the company's name, e-mail address and telephone number.

When a caller to the company is put on hold, the music keeping him occupied is, of course, The Beatles.

The company hasn't posted huge profits: For the year ended Jan. 1, 2005, Apple Corps claimed a loss of nearly $950,000.

It noted in financial statements filed with Companies House, the official government register of British companies, that more than $2.2 million each was paid for the "promotional services" of McCartney, Starr, Yoko Ono and Olivia Harrison.