ATLANTA — Cox Automotive Inc. has voluntarily withdrawn its filing under the Hart-Scott-Rodino Antitrust Improvements Act in order to give the U.S. Department of Justice additional time to review its proposed acquisition of Dealertrack Technologies.

The act requires that parties to certain mergers or acquisitions notify the Federal Trade Commission and the Department of Justice before consummating a proposed acquisition. The parties must then wait a specific period, usually 30 days, to allow the regulating agencies to conduct a preliminary antitrust evaluation.

“A new waiting period under the HSR Act will begin when Cox Automotive resubmits its HSR filing, which is expected to occur on July 8, 2015,” Cox Automotive stated in a press release. “Cox Automotive and Dealertrack continue to work cooperatively with the U.S. Department of Justice staff in their review of the proposed transaction and expect to close the transaction in the third quarter 2015.”

On June 15, Cox Automotive announces that it had entered into a definite agreement to acquire Dealertrack in an all-cash transaction valued at $4 billion. The deal brings together two software giants that officials with both companies said has very little overlap.

Cox, which is expected to generate $5 billion in revenue this year, brings to the table digital marketing, wholesale and ecommerce solutions marketed through more than 20 brands, including household names like Manheim, Autotrade, Kelley Blue Book, vAuto, VinSolutions and Xtime, while Dealertrack, which posted first quarter revenue of $253 million, is an established leader in lending, digital marketing and retail software solutions. Combined, the two companies will have solutions that touch every part of the dealership.