Google Inc. (GOOG) disclosed that earlier this year, Apple Inc. (AAPL) rejected Google's new Google Voice phone service for the popular iPhone's application store.

Apple told the Federal Communications Commission last month that it hadn't rejected Google Voice for the iPhone. Google's new phone service hasn't yet been approved for the iPhone app store, but Apple said it is still studying it.

Google, Apple and AT&T Inc. (T) all were asked by the FCC about reports that Google Voice had been rejected for the iPhone store. The iPhone is carried exclusively on AT&T's network, which allows the telecommunications company to subsidize the cost of the phone.

Google originally kept confidential its response to the FCC's question about the company's discussions with Apple. But Google notified the FCC on Thursday that it was lifting its request for confidential treatment.

In a blog posting Friday, Google's Washington telecom and media counsel Richard Whitt said the company at first asked the FCC to redact that portion of its letter because it "involved sensitive commercial conversations between two companies."

According to the now-unredacted parts of Google's letter, Apple informed the company July 7 that it was rejecting the Google Voice application for the iPhone. "Apple believed the application duplicated the core dialer functionality of the iPhone," Google's letter said.

Apple told the FCC last month that Google Voice "appears to alter the iPhone's distinctive user experience by replacing the iPhone's core mobile telephone functionality and Apple user interface with its own user interface."

Apple didn't redact any portions of its letter.

Whitt said several people submitted Freedom of Information Act requests to the FCC for access to Google's redacted content.

"In light of Apple's decision to make its own letter fully public and in the interest of transparency, we decided to drop our request for confidentiality," he said.

The unredacted version of Google's letter to the FCC was posted on the FCC Web site Friday.

-By Fawn Johnson, Dow Jones Newswires; 202-862-9263; fawn.johnson@dowjones.com