Atlantic Research Corp., of Alexandria, became a publicly traded company yesterday through the successful sale of 524,000 shares of common stock at $10 apiece.

A spokesman for L. F. Rothschild, Unterberg, Towbin, a Wall Street firm that managed the Atlantic Research offering, described investor response as "excellent" and said the issue was sold out.

The diversified missile manufacturing, communications and research firm, founded in 1949, sold 300,000 shares yesterday while current stockholders sold an additional 224,00 shares. Atlantic Research now has 1.4 million common shares outstanding.

Before 1977, ARC had been a subsidiary of the Susquehanna Corp. Since then, it was operated as an independent firm owned by officers, directors and key employes.

In 1978, the Alexandria company has sales of $45 million and earnings of $1.27 million ($1.19 a share)

ARC has been known primarily for its work with the aerospace industry as a developer of small rockets and gas generators using solid propellants.ARC has been involved in such missile programs as Poseidon, Minuteman, Trident and the Tomahawk cruise missile, for which the firm is manufacturing a boost motor.

In addition to this specialty, ARC is engaged in a number of other enterprises - all under four main divisions.

ARC business lines include data communications, electromagnetic field measurement and analysis, radio and television consulting, specialized vehicles, microchemistry and printing.

The Alexandria company employes about 900 persons, mostly at facilities in Northern Virginia.