Sales of iPhones increased more than sixfold during the second quarter of 2009, helping Apple maintain its ranking as the third largest smartphone maker worldwide, according to a new report.

In an international review of mobile phone and smartphone sales, Gartner research director Carolina Milanesi reports that Apple sold more than 5.4 million iPhones in the second quarter of 2009. That number is well up from the 892,000 sold during that period in 2008, and represents the largest expansion of any smartphone maker. That growth brought the handset maker from a 2.8 percent market share to a 13.3 percent share of second-quarter sales in 2009.

In all, 40.9 million smartphones were sold during the period, representing 27 percent growth from 2008. Nokia was the worldwide leader, moving 18.4 million smartphones during the period, up from 15.2 million a year prior. Even with that increase, though, Nokia’s market share dropped from 47.4 percent to 45 percent, demonstrating that the smartphone market is becoming even more crowded and competitive.

Second globally was Research in Motion, which captured 18.7 percent of the market, selling 7.6 million phones. In fourth was HTC with 6 percent share, and Fujitsu was in fifth with 3 percent.

Apple initially moved into third place globally in the third quarter of 2008, as the iPhone has continued its expansion internationally. The impact of the recently launched iPhone 3GS will not be seen until the second half of 2009, the Gartner analysis said.

“Apple’s expansion into a larger number of countries in the past year has produced a clear effect on sales volumes, as have the recent price adjustments on the 8GB 3G iPhone,” the report states.