Apple in the second quarter became the world’s leading smartphone brand for the first time, according to new data from IHS iSuppli (

The company’s smartphone sales increased by 9.1% during the second quarter, helping it to rise one position from second place in the first quarter to become the world’s largest smartphone maker, says the research group. Apple also capitalized on a 31% decline in shipments at longtime market leader Nokia.

Apple’s iPhone line is playing a key role in the driving the rapid expansion of the smartphone market, says iHS iSuppli. Global smartphone unit shipments are expected to amount to 478 million units in 2011, up 62.4% from 294 million in 2010. Shipments will more than double by 2015, expanding to more than one billion units, per iHS iSuppli.

By 2015, smartphone shipments are expected to rise to account for more than half of all cellphones, says the research group. Smartphones will represent 54.4% of total global mobile handset shipments in 2015, up from 32.5% in 2011. Much of this growth is being driven by low-end models that are attractive to first-time users and to consumers in emerging economies where subscriber levels are rising at the fastest rates, including China, India, South Asia and Africa, says iHS iSuppli.