Amazon will open an Android app store that will directly compete with Google's Android Marketplace, according to a Thursday report from The Wall Street Journal.

The Journal got its hands on an Amazon document intended for developers, which said Amazon will take a 30 percent cut of a developer's sales. Apps can't be sold at a lower price in another app store, according to the document.

Within two weeks of accepting Amazon's terms of service, developers would have to put their existing apps in Amazon's store. They would also have to put future apps in the Amazon store within two weeks of being made available in any other store, the Journal said.

No word on when Amazon's store might open or what it would be called.

Amazon did not immediately respond to a request for comment. A Google spokesman said the company does not comment on rumor or speculation.

Last month, Verizon said that its Verizon Developer Community is now accepting submissions for apps running on Android 2.2, and that the Verizon App Store will be available on Android phones by year's end.