Usage of Microsoft Corp.'s Internet Explorer browser worldwide has slipped since January, while Mozilla Corp.'s Firefox gained by a nearly equal amount, a Web analytics firm said Friday.

IE use fell by 0.65 percent to 85.17 percent of the market in May, OneStat.com, a Dutch firm, reported. Firefox usage increased by 0.56 percent to 11.79 percent.

In the United States, IE usage was lower than it was globally at 82.47 percent, despite an increase of 1.56 percent since January, OneStat.com said. Firefox use was higher in the United States at 12.81 percent, rising 0.26 percent since January.

Apple Computer Inc.'s Safari was the third most popular browser globally and in the United States, followed by Opera and Netscape. Globally, Safari and Opera has increased in popularity since January, but usage for both fell in the United States.

In January, OneStat.com reported that IE's share rose in the last two months of 2005 to 85.8 percent globally and 80.9 percent in the United States. Firefox had slipped to 11.2 percent and 12.6 percent, respectively.