Microsoft's claim that Internet Explorer 8 (IE8) and IE9 beat the usage share gains posted by Chrome last month don't hold up, according to the data the company cited Monday.

But the matter may be moot: Overall, IE again lost ground to Google Chrome and Apple's Safari in the battle for browser hearts and minds.

In a post to a company blog, Ryan Gavin, a senior director on the IE team, said that IE8 and IE9 boosted their combined global usage shares by 0.45 of a percentage point, and compared that to what he called Chrome's increase of just 0.19 of a percentage point.

"Our latest browser offerings saw a 0.45% increase in market share this month worldwide..., [a] higher worldwide growth than Chrome's Stable and Beta channels," said Gavin. Gavin cited October browser usage share numbers published today by Net Applications.

To arrive at his conclusion, Gavin measured gains made during October by IE8 and IE9 against a mix of Chrome versions. Gavin calculated Chrome's increase of just 0.19 of a percentage point by comparing the combined share of Chrome 5, Chrome 6, Chrome 7 and Chrome 8 in September (7.69 points, Gavin said) against the total of Chrome 6, Chrome 7, Chrome 8 and Chrome 9 in October (7.88 points).

But by tossing Chrome 5, Gavin struck 0.27 percentage point from Google's total, skewing the comparison in IE's favor. If Chrome 5 is added to the mix, Google gained 0.46 percentage point, virtually the same as IE8 and IE9, during the month.

Microsoft did not immediately reply to questions about its claims, and why it did not include Chrome 5 in its comparison.

While Microsoft touted IE8 and IE9 increases, total IE share continued to slip. Microsoft's browser accounted for 59.3% of all browsers used worldwide during October, Net Applications said, down 0.4 of a percentage point from the month prior. The mark is another record low for IE, and the third month of declines in a row after a two month run of gains over the summer.

Chrome was the biggest beneficiary of IE's losses, ending October with an 8.5% share, an increase of nearly half a percentage point. Meanwhile, Apple's Safari raised its share by less than one tenth of a point to 5.3%. Both browsers posted record share results last month.

Mozilla's Firefox and Opera Software's Opera were both down last month after showing very minor gains in September.

Firefox ended October with a 22.8% share, down more than a tenth of a percentage point and at the lowest point since July 2009. Mozilla's open source browser remained the overwhelming number two browser, however, with a share more than two-and-a-half times larger than number three, Chrome.

Opera slipped a tenth of a percentage point to 2.3%.

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