Under terms of the $400 million pact, Warburg Pincus will receive Avaya preferred stock it can convert to approximately 5 percent of Avaya's common stock. The investment firm will also receive warrants that will allow it to purchase another 3.6 percent of Avaya common stock.
A Warburg Pincus representative will also sit on Avaya's board.
The Avaya spinoff, announced in June, is scheduled to be completed in Lucent's fiscal fourth quarter, which ends Sept. 30, according to Lucent.
Avaya executives have said the former Enterprise Networks Group at Lucent had $8.3 billion in revenue and net income of about $300 million last year. The Basking Ridge, N.J.-based division sells phone systems called PBXs, corporate networking and messaging, and structured cabling products.
Lucent said last month that it would also spin off its networking and optical components business. John Dickson, 54, was named chief executive of the company earlier this week. Dickson has been with Lucent since 1993 and was named group president of the microelectronics unit in 1998.
Separately, Lucent's microelectronics group today announced a five-year, $700 million research and development agreement with Chartered Semiconductor Manufacturing to jointly develop ways to build communications components.