DALLAS -- Southwest Airlines plans to sell live television service on five planes and expand it to more aircraft by mid-July.

The airline said Thursday that it would offer seven sports and news channels for passengers to watch on their own devices.

Southwest said it will test prices from $3 to $8 during a trial period. Passengers will need a Wi-Fi-enabled device such as a smartphone, tablet or laptop computer.

Live TV will be offered separately from wireless Internet access and customers won’t have to buy Internet access to watch TV.

The Southwest channels: NBC Sports, MLB (Major League Baseball), NFL Network, CNBC, MSNBC, Fox News and Fox Business News.

Southwest hired Row 44 to provide the service, which the airline plans to expand to 20 planes by mid-July. Southwest said that if the service is successful, it will be added to all the airline’s Wi-Fi-enabled planes by the end of the year.

The airline has about 550 Boeing 737 jets including about 250 with Wi-Fi. It plans to outfit 70 percent of its fleet by the end of 2013.

Airlines have been expanding in-flight entertainment options such as Internet access to distinguish themselves from other airlines that often sell tickets for about the same price.

JetBlue Airways and Virgin America have offered live TV programming on seat-back screens for several years at no extra fee. They provide 36 and 18 channels, respectively. Frontier Airlines sells 25 channels of live satellite TV on its larger planes for $6, with elite-level frequent fliers getting it free. United charges $6 for flights under two hours and $8 for longer ones but hasn’t outfitted its entire fleet.

Separately, Delta Air Lines said Thursday that it will offer Internet access on international flights beginning early next year. Delta’s entire domestic fleet is already outfitted for Wi-Fi, but airlines have been slower to add the service on overseas routes partly because they need satellites to get a signal over the middle of the ocean, not the land-based transmission signals often used within the U.S.