Global mobile broadband subscriptions for the third quarter grew about 40 percent annually and topped two billion, accounting for a large portion of the 6.6 billion mobile subscriptions worldwide.

Ericsson’s latest mobility report sees the growth trend for mobile broadband continuing, predicting mobile broadband subscriptions will quadruple by 2019, hitting eight billion worldwide.

Ericsson’s report partly attributes the uptick in mobile broadband subscriptions to big smartphone sales for the quarter, with smartphones accounting for 55 percent of all handsets sold during the third quarter.

For now, GSM/EDGE-only subscribers represent the largest portion of total mobile subscribers worldwide due to rising demand in developing global markets. But Ericsson predicts that LTE will see substantial gains over the next few years, jumping to 2.6 billion subscriptions by 2019. North America will remain a big factor in LTE growth, with U.S. subscriptions expected to hit 85 percent in 2019.

Regardless of network, mobile data traffic continues its meteoric rise worldwide, growing 80 percent annually for the third quarter. To put that in perspective, Ericsson noted that the amount mobile data traffic rose quarterly in the third quarter is more than the total of mobile data traffic for the fourth quarter of 2009.