Knight Transportation Inc. KNX, -0.33% and Swift Transportation Co. swft said Monday they are merging in an all-stock deal with a combined enterprise value of $6 billion. The combined entity will be called Knight-Swift Transportation Holdings Inc. and will trade under the ticker "KNX", the companies said in a joint statement. The deal "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," said the statement. The company will remain headquartered in Phoenix, Arizona with about 23,000 tractors, 77,000 trailers and 28,000 employees. Under terms of the deal, each Swift share will convert into 0.72 shares of Knight-Swift via a reverse stock split. Each share of Knight will be exchanged for one Knight-Swift share. The deal is expected to boost adjusted per-share earnings in the second half of 2017, adding about $15 million, followed by $100 million in 2018 and $150 million in 2019. The deal is expected to close in the third quarter, Knight shares rose 0.5% in premarket trade, while Swift shares were not yet active.