Google, the dominant search leader, grabbed 72.15 percent of all US searches in the four weeks ending October 2, according to Hitwise, an online traffic monitor. That's up slightly from 71.59 percent in August.
Microsoft Bing, which is Google 's biggest rival, didn't have such a great month in September.
Hitwise reported on Friday that Bing-powered search sites received 23.64 percent of US searches for the month, with Yahoo grabbing 13.54 percent and Bing itself pulling in 10.10 percent. Bing-powered search sites are down two percent overall, while Yahoo is down five percent. Bing itself went up two percent.
Microsoft and Yahoo announced in August that Bing is fuelling Yahoo search results in the US and Canada. The search integration came more than a year after both companies announced they were joining forces to better take on Google - since neither company had made any headway on its own.
The latest Hitwise report shows that Yahoo suffered after integration, while Bing saw only a small bump.
"It's a pretty small slip and only based on a month's worth of data," said Dan Olds, an analyst with The Gabriel Consulting Group. "I'm sure that these aren't the results that Bing marketers are looking for... but the Christmas season might be key for them. Search engines receive a real workout with all of the holiday shopping, travel planning and the like. It will be interesting to see how Bing fares over the next three months or so."
See also: Google versus Microsoft Bing