SUNNYVALE, Calif., June 17, 2013 /PRNewswire/ -- ShoreTel® (NASDAQ: SHOR), the leading provider of brilliantly simple unified communications platforms including business phone systems, applications and mobile UC solutions, continues to gain market share in the IP telephony market in the United States according to recent data published by Synergy Research Group. In its market share summary report for the first calendar quarter of 2013, Synergy found that ShoreTel had both the highest sequential market share and revenue growth rates for Enterprise IP Telephony compared to Avaya Inc., Cisco Systems, Inc. and Mitel Networks Corporation. In addition, ShoreTel gained market share in the Unified Communications as a Service (UCaaS) Private Network segment, and retains the number one position in that market. According to Synergy data based on revenue, ShoreTel ranks third in Enterprise IP Telephony market share in the U.S. with a revenue increase of 7 percent over the previous quarter, and the company grew its market share from 6.4 percent in Q4'12 to 8.0 percent in Q1'13, a 25 percent increase in quarter over quarter market share growth and 13 percent year over year market share growth. In contrast, Synergy reported for the same U.S. market that Cisco's revenues dropped 18 percent; Avaya's revenues dropped 26 percent and Mitel's revenues dropped 22 percent. Synergy also reported that ShoreTel increased its leading market share position in the U.S. in Q1'13 to 34 percent in the UCaaS Private Network segment for services most commonly targeted to larger businesses. "ShoreTel continues to gain in market share over our largest competitors who have experienced declining sales," said Peter Blackmore, ShoreTel CEO. "By offering customers ultimate choice and flexibility in both on-premise and cloud solutions, we continue to win business. With investments in customer satisfaction programs, hybrid infrastructure, as well as our strong partner ecosystem, we expect to see continued long-term growth." "By addressing both the existing IP telephony and emerging Cloud UC market, ShoreTel is executing on a bold strategy which is reaping market share gains presently and positions ShoreTel as a major competitive force in the future," said Jeremy Duke, founder and chief analyst, Synergy Research Group.