William Adolph Barq, 79, a third-generation president of Barq's Inc., maker of the nation's top-selling root beer, died of cardiac arrest Tuesday in Biloxi, Miss.

In 1962, Mr. Barq took over as president of the family soft drink business. Barq's root beer was first bottled in 1898 in Biloxi by his grandfather, Edward C. Barq Sr., a sugar chemist by trade.

In 1976, John Koerner and John Oudt acquired the company from the Barq family and moved the headquarters to New Orleans while the syrup continued to be made in Biloxi.

In 1995, Coca-Cola Co. completed purchase of Barq's Inc. and moved the headquarters to Atlanta.