Avaya has committed to keeping 60% of the North American employees of Nortel Networks' enterprise business.
Avaya outbid Siemens Enterprise Communications with a $915m offer for Nortel's enterprise networking operation in a three-day bidding contest.
The takeover, set for December, could put Avaya ahead of current enterprise networking market leader Cisco.
The commitment to 60% staff retention is a climb-down from the 75% originally indicated by Nortel enterprise executive Joel Hackney, according to Canadian reports.
European legislation means that most Nortel enterprise group staff in the region will also transfer to Avaya.
Avaya also plans to hire all the employees in a Washington-based government services operation, which may be linked to concerns raised by Verizon over servicing for US critical infrastructure.
Citing concerns largely around public safety and security, Verizon claimed Avaya was refusing to honour contracts with Verizon customers, which include the US military, anti-terrorism agencies and Congress.
Verizon filed an objection in the US Bankruptcy court for the District of Delaware related to Avaya's bid for Nortel Enterprise Solutions.
Avaya said in a statement that it was committed to providing current and future customers with the highest level of service and support.
"Avaya is engaged in discussions with Verizon to attempt to negotiate suitable arrangements for the assumption of the contracts referenced in Verizon's motion," the statement said.
Picture: Rex Features