Google has cited Apple's Siri voice assistant as an example of why it believes that it should not be being investigated by an anti-trust committee in the US.

Google's dominance of the search engine has led to a probe by the authorities into whether it places its own properties higher in its own rankings, but chairman and former CEO Eric Schmidt pointed to Siri as an example of the way in which the business is evolving.

Schmidt's statement, published on Google Docs said: "Moreover, history shows that popular technology is often supplanted by entirely new models.

Apple

"Even in the few weeks since the hearing, Apple has launched an entirely new approach to search technology with Siri, its voice-activated search and task-completion service built into the iPhone 4S," he added.

"As one respected technology site reported: "[E]veryone keeps insisting that Apple will eventually get into the search engine business.

"Well they have. But not in the way that everyone was thinking. Siri is their entry point." Another commentator has described Siri more simply as intended to be a "Google killer."

The two cited sources, by the way, are TechCrunch and Forbes.

Under pressure

Schmidt then told the committee that Google was under pressure to be high in the rankings, insisting the whole premise of favouring its own products is based on an 'inaccurate premise'.

"These universal search results are our search service—they are not some separate 'Google product or service' that can be 'favored.'" said Schmidt.

"The fundamental openness of the Internet places powerful competitive pressure on Google to ensure that our search results are those that are most responsive to what users are looking for."

Daily deals company Groupon finally began training on the NASDAQ stock exchange on Friday with shares experiencing an initial 46 per cent hike in value.

The Groupon float has long been in offing and is one of the most eagerly anticipated tech company IPOs of recent times.

The company priced an initial offering of 35 million shares - about 5 per cent of its actual holding - at $20 (£12) a share, but they soon jumped to $29.20 - a 46 per cent increase.

A $20 a share, the company is valued at a whopping $12.7 billion (around £8 billion).

Focus on long-term business

"Today's a significant step in Groupon's journey, but it's not the finish line," a company spokesman said.

"We're committed to innovating ways to change local retail for consumers and local businesses.

"It's great to pause and recognize what we've accomplished, but we're focused on building a long-term business that really changes people's expectations of local commerce."

The IPO, although months in the offing, still caused a little bit of drama on launch day, failing to debut on the NASDAQ until an hour after trading began.