telephonecloudkitesbwUnified communications (UC) providers 8×8 and RingCentral are the two companies dominating the UC-as-a-service (USaaS) market in the third quarter of 2014, according to a new study by Synergy Research Group. 8×8 and RingCentral each own a market share of just under 13 percent, cementing them as the twin 800-pound gorillas in the UCaaS market.

Current OTT (Over the Top Technology) UCaaS figures accounted for 57 percent of quarterly business suite revenues, while private circuit UCaaS accounted for 30 percent of revenue, according to the study. Hybrid deployments made up the remainder of third-quarter revenue. North America continues to be the largest UCaaS market in the world, claiming 85 percent of total worldwide revenue.

Mitel Networks (MITL), meanwhile, continues to gain ground and market share, with the company adding a 60 percent year-on-year increase in revenue and adding more than two times the number of subscribers to become the fastest growing company in the industry. The company has also reported a 30 percent year-over-year increase in market revenues.

Mitel has been a hot name in the UCaaS market for the past several months, with the company aggressively pursuing an acquisition of ShoreTel (SHOR), a rival unified communications company. Earlier this month, Mitel CEO Richard McBee penned his third letter to ShoreTel’s board of directors, following a proposed acquisition price increase to $8.50 per share, or roughly $574 million.

“This is an exciting and disruptive market which is shaking up the old order in enterprise communications, enabling UC to be more broadly adopted in smaller offices and planting the seed for cloud deployments in mid-to-large enterprises,” said Synergy Research Group’s founder and chief analyst Jeremy Duke, in a statement. “The recent tussle between Mitel and ShoreTel clearly demonstrates how important UCaaS and cloud are to traditional enterprise UC vendors and we expect to see more such activity.”

Thus far, ShoreTel has rebuffed all of Mitel’s attempts to acquire the company. Following the Mitel’s most recent offer, ShoreTel’s board urged its stockholders to exercise restraint in selling off their shares until the offer could be properly reviewed. ShoreTel has remained quiet on whether it plans to accept the terms of the acquisition.