NEW YORK (Bloomberg) — Google Inc. upgraded the way it presents search result images to simplify web navigation and keep competition with Microsoft Corp. and Yahoo! Inc. at bay.

The updated service, called Instant Previews, gives users graphic snapshots of search results, and then highlights the most relevant parts of the websites, said Ben Gomes, an engineer at Google. The features were rolled out in the US and abroad yesterday.

"What this allows you to do is compare the various results to pick the one that most appeals to you," Gomes said. Users, who activate the service by clicking on a magnifying glass icon, are about five percent more likely to be satisfied with their results, he said, citing early testing by the company.

The company is making the upgrade to keep its lead in the $12.4 billion US market for search-related advertising after Microsoft and Yahoo signed a search-engine agreement designed to help them vie with Google. The company had 66 percent of US searches in September according to ComScore Inc. in Reston, Virginia. Yahoo had 17 percent, while Microsoft had 11 percent.

In September, Google unveiled its Instant service, which gives users search-results pages as they type in queries. The company said that feature can save two to five seconds per search.

Google, based in Mountain View, California, rose $2.71 to $629.48 at 10 a.m. New York time in Nasdaq Stock Market trading. The shares had climbed 1.1 percent this year before today.