Microsoft's search engine suffered a steep usage drop in May, right before the company launched Bing, a new version of its search engine, according to the latest market share figures from Nielsen Online.

US residents ran almost 15 percent fewer queries on Microsoft's search engine in May year-on-year, although search queries grew 20.3 percent in the market overall, Nielsen Online said.

Microsoft's Live/MSN search engine was the only one among the top five that saw its search usage shrink last month compared with May 2008.

Google, which ranked first with a 63.2 percent share of queries, registered a 28.2 percent growth in queries. Yahoo, in its usual distant second place with a 17.2 percent share, had its queries grow 22.3 percent. AOL, with a 4 percent share, registered growth of 13.1 percent, while (2.2 percent share), grew its queries 22 percent.

The MSN/Live search engine ranked third with a 9.4 percent share of queries.

Microsoft has high hopes for Bing, which it announced in late May and began to roll out days later with great fanfare.

Microsoft calls Bing a "decision engine" designed to give people a "first step" to move beyond what the company calls the conventional search experience by making it easier to find and use information on the web.

Despite Google's dominance, Microsoft maintains that the search market is still in its early stages and that many opportunities exist to improve upon the search-engine user experience.

Microsoft Bing review