A McLean fast-food restaurant owner who has dabbled in real estate beat out some of the area's most prestigious builders this week in a bankruptcy-auction bidding battle for a house on 7.3 acres adjacent to Hickory Hill, home of Ethel Kennedy.

George Zachary Kontzias is paying $1,175,000 for the land, which faces Chain Bridge Road near Ballantrae Lane south of the Central Intelligence Agency in the Langley community.

The site includes a three-level, 12-room house with 6 1/2 bathrooms. Kontzias said the house needs major renovations.

If he decided to develop the land, there could be a new subdivision of six homes on one-acre lots next to Hickory Hill.

Although Kontzias and his wife, Helen, plan to move into the house after updating it, the land investment is a "gold mine," according to a Fairfax County staff member.

The land is zoned for one house per acre and would yield six new building lots that developers estimate would be worth at least a quarter of a million dollars once necessary site preparation work is completed.

Homes built on those lots could sell for $1.5 million each, according to McLean-area builders.

The sale culminates years of complicated litigation. The property was sold at auction Wednesday in U.S. Bankruptcy Court in Alexandria as a result of the bankruptcy of Philander P. Claxton III. Claxton was once head of a McLean-based company known as the Watkins Corp.

In 1977, Claxton won world attention when he and a co-pilot set a record for flying around the world in a twin-engine plane.

The house, built in 1949, was hailed for its creative design and was featured in a 1951 Washington Star real estate section.

Kontzias' offices are now above his Zach's Drive-In Restaurant in McLean's central business district, but he is best known as the man who ran Zachary's, an award-winning Greek restaurant that he owned and operated in the Chesterbrook shopping center near the Arlington line from 1975 until January 1983.

He was recently named McLean's businessman of the year by a local business group.

Kontzias' bid topped an offer by those who have built some of McLean's most expensive homes.

Builders losing out included Dwight Schar, a principal of NV Cos., who is also developer and resident of the exclusive development known as Ballantrae; John G. Georgelas, head of John G. Georgelas & Sons residential and commercial builders, and Randy Williams, past president of the Northern Virginia Builders Association.

Williams now builds homes priced to sell over $450,000. Ironically, Schar lives at Ballantrae across Chain Bridge Road from the Kontzias property, and Georgelas is building a home there.

"We plan to live there," said Kontzias, whose wife first saw an ad in a local newspaper a week ago announcing the bankruptcy auction. "I love the older home," he said. When asked if he has plans to develop the land, Kontzias said such a decision would be "premature." But he added: "God doesn't make any more land."

Land near his new home is hard to come by and expensive. The estates of developer Alan Kay, Gov. Charles Robb, and Sen. Edward Kennedy are east of the site. Virginia State Sen. Clive DuVal's historic home, Salona, is between Kontzias' new home and McLean's business district.

Kontzias left Greece in 1954 for Montreal, where he worked as a dishwasher, earning a little more than $12 a week, he said. In 1969, he opened a restaurant in Arlington that he operated until 1975, when he opened Zachary's in McLean.

Zachary's won rave reviews from Washington restaurant critics until he closed it last year because running that kind of restaurant left him little time to do anything else, he explained.

He now owns Zach's, a quick-service establishment that requires far less of his personal time, and has set up his own real estate company. He said he plans to be involved in the redevelopment of some existing older commercial sites in McLean.