Trucking company Swift Transportation Co's second-quarter profit beat market expectations on stronger pricing and growth in intermodal volumes, sending its shares up 7 percent after the bell.

Swift Transportation, whose largest customer is retailer Wal-Mart, said it expects adjusted earnings growth of 20 percent this year.

The company is primarily a truckload carrier but it also has rail intermodal, freight brokerage, and third-party logistics operations. It expects intermodal container growth of 2,000 units from July to November.

Intermodal refers to the shipment of goods in containers that can be shifted from one form of transportation to another, such as from truck to train.

Net income rose to $33.7 million, or 24 cents a share, from $19.6 million, or 14 cents a share, a year ago. Excluding items, the company earned 27 cents a share.

Operating revenue grew 3 percent to $872.6 million.

Analysts had expected were expecting earnings of 23 cents a share on revneue of $882.8 million, according to Thomson Reuters I/B/E/S. (Reuters)