The mega-merger of Knight Transportation and Swift Transportation has moved a step closer to completion with the Federal Trade Commission granting its approval.

The antitrust approval came quickly, in the form of an early termination notice posted by FTC on May 1. That action allows shareholders to vote on the deal, which is expected to close this summer. However, the merger must still be approved by the Securities and Exchange Commission and meet other requirements before the deal can legally close.

Once they are merged to form Knight-Swift Transportation Holdings, the two carriers will together field the largest truckload operation in the U.S. The new company is projected to generate annual revenues over $5 billion and boas a market capitalization of about $6 billion.

The Phoenix-based companies announced on April 10 that their respective boards of directors unanimously approved the merger of Knight and Swift in an all-stock transaction that they said will create the industry's largest full truckload company. 

“This transaction combines under common ownership two long-standing industry leaders creating North America's premier truckload transportation company with $5 billion in annual revenue and a ‘Top 5’ truckload presence in dry van, refrigerated, dedicated, cross-border Mexico and Canada, and a significant presence in brokerage and intermodal,” the companies said in a joint statement.

The new holding company will remain headquartered in Phoenix and will operate with some 23,000 tractors, 77,000 trailers, and 28,000 employees. 

The companies noted that, post-merger, the distinct Swift and Knight brands and operations will be maintained.

Related: Knight-Swift: A Merger of Mindsets