Mobile search use is growing more widespread and more frequent in the US and Western Europe - 20.8 million US and 4.5 million European mobile phone subscribers used search in June - up 68% and 38%, respectively from June 2007, comScore M:Metrics reports.

The UK had the highest penetration of mobile subscribers using search (9.5%), followed closely by the US(9.2%).

The number of people accessing mobile search at least once a week grew 50% in Europe, with France and Spain leading at a rate of 69% and 63%, respectively:

“Meanwhile, the number of US users accessing mobile search has more than doubled as a result of expanded 3G penetration and smartphone adoption, as well as the proliferation of flat-rate data plans. We have also seen a substantial improvement to the mobile search offerings in the US market,” said Alistair Hill, an analyst at comScore.

Google is the preferred brand for browser-based searches with a 60% share of mobile searchers (”mobile searcher penetration”) in all countries measured by comScore M:Metrics:

Yahoo ranks second in Germany, Italy, UK and the US In the US, Yahoo’s mobile searcher penetration is 34.6%, more than double its share in most other countries.