Apple has sent notice to Lodsys, as well as developers targeted by the patent holdings firm, saying it has licensed the rights to in-app purchase, and that that license extends to developers on the iOS platform.

Developers MobileAge, the makers of the game Shanghai lite, received a letter from Apple's senior vice president and general counsel, Bruce Sewell, this morning telling them that the company has already licensed the four patents in Lodsys' portfolio, and that said license allows Apple's customers and business partners similar coverage to use it.

"Apple is undisputedly licensed to these (patents) and the Apple App Makers are protected by that license," Sewell wrote. "There is no basis for Lodsys' infringement allegations against Apple's App Makers."

Lodsys CEO Mark Small did not immediately respond to a request for comment. The firm said in its FAQ about the issue that it will not speak to the press.

Lodsys, triggered a controversy earlier this month when it began going after developers--instead of Apple--in seeking a licensing fee on apps that made use of the in-app purchase (IAP) feature, threatening those who did not comply with legal action.

"Because Apple is licensed under Lodsys' patents to offer such technology to its App Makers, the App Makers are entitled to use this technology free from any infringement claims by Lodsys," Sewell wrote.

Apple's response agues that the illustrated infringement of that Lodsys patent is further flawed in that it relies on Apple's application programming interfaces, Apple's Apple ID system, and its hardware, software, and servers.

In the letter, Apple requests that Lodsys withdraw letters sent to developers about the issue, as well as "cease its false assertions that the App Makers' use of licensed Apple products and services in any way constitute infringement of any Lodsys patent."

"It's definitely smiles around here in the office," said MobileAge President Ken Landau in a phone interview. "Now we have a letter from Apple saying they have the rights to the patents, and partners and developers have rights to use it. That's good because Shanghai is very popular, and it helps pay the bills."

Below is a full copy of the letter: