NASHVILLE (AP) - The U.S. Department of Justice has filed an antitrust lawsuit to block Standard Parking Corp.'s acquisition of Central Parking Corp.

In a news release, the department said it will require Standard and Central to divest their interests in certain parking facilities in 29 cities before they can proceed.

Chicago-based Standard and Nashville-based Central are the two largest parking management companies in the U.S.

In its complaint, the department said the companies compete on prices, hours of operation and other terms. The competition benefits consumers, and the proposed merger threatens to end that competition.

The divestiture is part of a proposed settlement filed Wednesday in U.S. District Court for the District of Columbia at the same time as the suit.

The acquisition is valued at approximately $345 million.