Microsoft's new search engine Bing continued to sees gains in US searcher penetration and share of search result pages during the second week after its public launch, according to a follow-up study on its performance by comScore, Inc.

The qSearch analysis revealed that Microsoft Sites' average daily penetration among US searchers reached 16.7% during the work week of June 8-12, up three percentage points from 13.8% during the May 25-29 work week prior to Bing's introduction, MarketingCharts observes.

Microsoft's share of search result pages in the US, a proxy for overall search intensity, increased to 12.1% during the period of June 8-12, and also climbed three percentage points from the work week of May 25-29, 2009.

An earlier comScore analysis conducted during the first week after Bing's public launch found that the new search engine's average daily penetration was 15.5% and its share of search result pages was 11.1% during the period of June 2-6, 2009.

"It appears that Microsoft Bing has continued to generate interest from the market for the second consecutive week," said Mike Hurt, comScore SVP. "These early data reflect a continued positive market reaction to Bing in the initial stages of its launch."

The New York Post reported that Bing's early success has "rattled" Google co-founder Sergey Brin, who is said to be leading a team of top engineers in a quest to discover how Bing's algorithm works and to complete performance upgrades to the Google system.