Overture Networks completed a $7.5-million third round of funding, the company announced today.

The round was led by a new investor, the Telecommunications Development Fund, a Washington, D.C.,-based venture capital fund with $50 million and a focus on the telecom industry.

Existing Overture investors Morgenthaler Ventures, Intersouth Partners, Armada Ventures and Gray Ventures joined another new investor, Legend Investors (which is also an investor in Ethernet equipment vendor Atrica), in the round.

Six-year-old Overture sells circuit-bonding equipment that consolidates T-1s and other links for greater reach and bandwidth.

With the help of partners such as Tellabs and ADC, Overture claims to have achieved double-digit quarterly revenue growth and more than 60 customers, including Cypress Communications and Memphis Networx.

Overture announced a $15-million round in 2002 that also gave a board seat to Krish Prabhu, who was at the time a partner at Morgenthaler Ventures, which led that round as a new investor. Prabhu, now the chief executive officer of Tellabs, is no longer an Overture director, but Alcatel’s retired former chief technology officer Niel Ransom recently took a seat on Overture’s board.