In Southampton, telecommunications mogul Donald Burns is preparing to list his massive house on Lake Agawam for $48 million, according to a source with knowledge of the listing.

Located on 10.5 acres, the grand home has a distinguished legacy since it was built in 1911. Architect Goodhue Livingston, of the renowned firm Trowbridge & Livingston, both owned and designed the home-which measures over 20,000 square feet. Mr. Livingston's firm also designed such notable buildings as the St. Regis Hotel, the J.P. Morgan headquarters on Wall Street, and the Hayden Planetarium.

Decades later, the family of Hamptons real-estate broker Michael Shaheen owned the palatial house, before selling it to Mr. Burns for around $20 million in 1999.

The sprawling property is comprised of three parcels: in addition to the main house, there is a 19th century barn and a seperate guest cottage. Also, there are two pools (one for the guest house, of course), a spa, and tennis courts.

Brokers Jay Flagg and Raymond Smith, of Prudential Douglas Elliman, will be listing the property, according a source. Mr. Flagg declined to comment.

- Michael Calderone