A pair of private equity firms are the winning bidders for communications manufacturer Avaya, Inc. (NYSE: AV).

TPG Capital LLC and Silver Lake Partners will pay $17.50 in cash per share of the corporate phone systems maker. The deal values shares of Avaya at 28 percent premium over Avaya’s May 25 closing price of $13.67, the last date before news of the potential buy broke out.

Basking Ridge, N.J.-based Avaya currently has a market cap of more than $6.1 billion. Its equipment helps direct voice and data traffic at almost all of the largest corporations in the U.S.

Last month, TPG was also involved in the $24.7 billion buyout of wireless firm Alltell Corp. (NYSE: AT)

We believe the enterprise telephony space is ripe for consolidation, where a large number of competitors continue to face off in the midst of a worldwide market transition to IP telephony, Prudential's Inder M. Singh told clients last week.

A former division of Lucent Technologies and its predecessor firm AT&T, Avaya also has patents and equipment for transforming traditional phone and data systems into integrated Internet Protocol-based networks.

The firm has long been rumored as a takeover target, given its small size relative to others in the industry.

Shares of Avaya rose 39 cents, or 2.33 percent to $17.11 in morning trading on the New York Stock Exchange.