Google's share of U.S. searches has been decreasing in tiny increments during July and August, in what may be merely a seasonal fluctuation - or an indication that the search giant has reached a plateau, writes Internet Retailer.

According to July and August search data from Hitwise, Google's share of U.S. searches has decreased from 60.23 percent for the four weeks ended July 29 to 59.84 percent for the four weeks ended August 19. Meanwhile, Yahoo's share of searches for the same periods have increased, from 22.54 percent to 22.77 percent - as have MSN's from 11.77 percent to 12.0 percent.

"While 60 percent may represent a saturation point for Google, it also may be a seasonal fluctuation," writes Hitwise global general research manager Bill Tancer in his blog. "A review of the same time period last year, reveals a similar trough in visits…bolstering the theory that we may be witnessing a seasonal trend."

Danny Sullivan of Search Engine Watch offers a thorough discussion of recent comScore, Nielsen and Hitwise data related to Google and the search market.