Apple and AT&T Mobility have won court approval to settle a lawsuit claiming the companies promoted and then quickly discontinued an unlimited data plan for customers who purchased an iPad 3G.

U.S. District Judge Ronald M. Whyte in San Jose, California, gave his preliminary approval last week to the agreement.

The agreement is “fair, reasonable, and adequate,” Whyte wrote in his order. Lawyers for the companies and plaintiffs must return to court for a Feb. 7 final approval hearing, he said.

Noted tech website Gigaom: “Under the deal, which is set to receive final approval in February, Apple will attempt to contact everyone who is eligible, and will send them a $40 check. The AT&T discount will also be available to those who no longer own their original iPad. (Those who signed up with any data plan with AT&T are shut out from the discount, however, owing to a no-class action provision in the carriers’ contracts.)”

GigaOm also provies a link to the details of the settlement.

The lawsuit consolidated four cases filed in 2010 with similar claims that the abrupt discontinuation of the “flexible access” data plan after an initial wave of iPad 3G purchases caused customers to overpay for the devices, and amounted to misrepresentation. AT&T, the largest U.S. phone company, had exclusive rights to the iPhone until 2011.

Kristin Huguet, a spokeswoman for Cupertino, California- based Apple, didn’t immediately return an e-mail seeking comment on the settlement.