By Josh Ong

Published: 02:10 AM EST (11:10 PM PST)

Apple has tightened restrictions on its iOS App Store by requiring all in-app purchases to go through it, resulting in the rejection of an eBookstore application from Sony, a new report claims.

Update: Apple has denied the claim.

The Cupertino, Calif., company has told applications developers, including Sony, that it will no longer allow developers to sell content and provide access to purchases outside the iOS App Store, The New York Times reports.

According to the report, Apple rejected a Sony Reader iPhone application that would let users buy and read e-books from the Sony Reader Store. Steve Haber, president of Sony's digital reading division, said that Apple told Sony that from now on, in-app purchases must go through Apple.

“It’s the opposite of what we wanted to bring to the market,” said Haber. “We always wanted to bring the content to as many devices as possible, not one device to one store.”

Rival ebook vendor Amazon could stand to lose. Amazon currently offers its Kindle e-book app on Apple's App Store, despite the fact that its Kindle e-reader competes with the iPad and iBookstore. The Kindle got an early start in the e-reading market, but has since lost significant ground to the iPad.

In December of last year, Amazon announced that the third-generation Kindle had become the best-selling product in the online retailer's history. Amazon CEO Jeff Bezos also noted at the time that many Kindle purchasers already own an LCD tablet, such as an iPad.

Analysts were taken aback by Apple's new restrictions, as they represent a shift away from recent attempts to be more collaborative.

Last fall, after receiving criticism for App Store restrictions that were viewed as "anti-competitive," Apple removed its ban on third-party development tools. With the more open licensing terms, Adobe resumed development of its Packager for iPhone tool for porting Flash to iOS.

Rival Google also gained from the changes, as its Google Voice application was accepted into the App Store. After Apple pulled Google Voice-enabled iPhone apps from the App Store, the US FCC launched an investigation of Apple and AT&T.

“This sudden shift perhaps tells you something about Apple’s understanding of the value of its platform,” said Forrester Research analyst James McQuivey. “Apple started making money with devices. Maybe the new thing that everyone recognizes is the unit of economic value is the platform, not the device.”

Later this week, News Corp, in direct partnership with Apple, will unveil The Daily, an experimental iPad-only digital newspaper. Apple's new restrictions could be a preemptive move ahead of the launch of a new subscription feature for the iPad.

Apple has reportedly told several European publishers that it will employ "stricter rules" that forbid free iPad access to paid print subscribers. By doing so, publishers could bypass Apple and its 30 percent commission on App Store transactions.