Arthur Godfrey's gently rolling 1,970-acre estate near Leesburg has been purchased for more than $5 million for use as a second or third home by a Saudi Arabian price.

A Netherlands Antilles corporation is identified in court papers as the nominal buyer of the radio and television entertainer's luxurious cattle and horse farm, called Beacon Hill and located 30 miles northwest of Washington.

But Prince Talal Bin Abdul Aziz Saud, half-brother of Saudi King Khalil, personally guaranteed a $3,150,000 mortgage for the estate, payable in five years.

The prince, a former Saudi finance minister now known as a businessman, plans to visit the estate occasionally and use it as his "second home - third home," according to a lawyer for the purchase.

The purchase was described yesterday as maintaining Godfrey's preservationist hopes for his secluded estate, about one mile northwest of Leesburg.

"It's a retreat, a farm," said Mitchell Cutler, the Washington attorney who represented the buyers.

They will "keep it as it's been and improve the house," Cutler said in a telephone interview. The prince and his American partners in the purchase have "no intention of developing it whatsoever."

Stewart B. Knower, a partner in a Leesburg real estate firm that first listed Beacon Hill for sale in 1977, described the Godfrey family as "delighted" with the purchase. The asking price was $6 million. The buyers paid about $5,150,000. But most importantly, Knower said, the new owners plan to preserve the character of the land.

"We had a number of people look at it with wholesale butchery in mind," Knower noted. Such developers considered splitting the estate into small lots or transforming it into an industrial venture. "As conservationists, we happen to like our countryside out here and we're just delighted that the land is being held intact," Knower added.

Neither Prince Talal nor the other buyers could be reached for comment. The Saudi Arabian Embassy declined to comment on the transaction. Cutler said it was a private and not a Saudi government purchase.

The estate - with stables, indoor riding ring and skating rink, outdoor pool and a six-bedroom, Tudor-style main house built in 1912 - was purchased by a corporation called Vanguard Company, registered in the Dutch territory that often provides tax and other advantages to foreign investors. The sale took place June 20, and was made public in Loudoun County Circuit Court records Wednesday.

The company's directors include Theodore A. Georgelas, an executive of a McLean architectural design and real estate firm, and Joseph L. Carlo-magno, described by his lawyer as a retired accountant. Cutler said that Carlomagno will "live out there (at Beacon Hill) and watch over the place."

In Leesburg, Godfrey, 75, is as much a hometown figure as a national show business celebrity. He has commuted regularly from his New York City apartment to the estate, which he began assembling in 1946. He has broadcast television shows from a transmitting tower built on the Loudoun County farm. The Leesburg airport is known as Godfrey Field.

Bryan Dubin, a spokesman for Godfrey's New York theatrical agent, said yesterday that Godfrey had just completed work on a new television special, filmed in part on his Virginia farm. "He's in excellent health. He still flies his own airplane," Dublin said. Officials said that despite the Beacon Hill sale, Godfrey and his wife Mary plan to keep a 90-acre tract nearby, where his wife, an enthusiastic horsewoman, will live.

In contrast, Prince Talal - who is said to be about 48 years old and the 23rd of 44 sons in the Saudi royal family - is a mystery to the people of Leesburg. They reacted yesterday with a mixture of curiosity, bantering, resignation and hopefullness.

There were jokes about Saudi oil, Saudi money and the current American gasoline crisis. There was jocular talk of a Saudi palace rising on Leesburg's doorsteps. But county government officials noted that Loudoun has been seeking foreign investments and said that the Godfrey estate appeared unlikely to be intensively developed because of current zoning restrictions and lack of water supply and sewer hookups.

"We're actively enticing foreigners to come into the county for economic and industrial development," said county zoning administrator James Van Zee. A Belgian furniture assembly plant recently opened east of Leesburg, and a West German plastics manufacturer is currently seeking county approval to set up its. North American headquarters nearby, Van Zee noted.

County appraisers expressed doubt that an estate as large as Beacon Hill would be viewed by financial speculators as a wise short-term investment. County appraiser Bill Gardner estimated that such property appreciated only by 5 to 10 percent in value annually, and he added, "You're dealing with a very limited market."

There was no clue yesterday to how the deal came about. Cutler declined to disclose the inner workings of the Vanguard Co.

Robert L. Schmidt of McLean, Godfrey's son-in-law who acted as Godfrey's attorney in the sale, issued a statement through his secretary, saying that the transaction probably would not be completed until today and that he could not comment about it before then.