GOOGLE has launched a stinging attack on major mobile phone rival Apple, saying its smartphone lawsuits are inspired by jealousy and a lack of innovation in its own iPhone.

The criticism, by former Google CEO and now executive chairman Eric Schmidt, follows the US International Trade Commissions initial ruling that HTC infringed two of Apple's phone patents in its Google Android-based phones.

If upheld, the decision could see Apple force other Android phone makers to pay significant royalties to their main competitor.

Speaking at Google's Mobile Revolution conference in Tokyo, Mr Schmidt said Apple's case was inspired by jealousy and designed to shut down its fastest-growing rival.

"The big news in the past year has been the explosion of Google Android handsets and this means our competitors are responding," he said.

"Because they are not responding with innovation, they're responding with lawsuits.

"We have not done anything wrong and these lawsuits are just inspired by our success."

Mr Schmidt said Google would support HTC's fight against Apple and was confident of a win, though he declined to go into details.

Mr Schmidt did reveal new details about Android smartphone growth, however, saying more than 550,000 Google-based phones were being activated daily — up from 400,000 per day in May.

More than 135 million Google phones have been activated since Android's launch in 2008, with 410 models available from makers including HTC, Motorola, Samsung and Sony Ericsson.

If the ITC's final decision — due in December — goes against HTC, it could have a significant impact on Android's future profitability. The two patents relate to data transmission and data detection in email and text messages.

Apple could fire another blow to Android with a new iPhone later this year as well.

The company is strongly rumoured to be launching the iPhone 5 worldwide in September. It is expected to come with a dual core processor, 8-megapixel camera, new iOS 5 software and iCloud services.