, the two companies said the four-year Innovative Communications Alliance (ICA) formed in 2006 was solid and intact. ICA is a plan to jointly develop, sell and roll out unified communications and VoIP technology to corporate customers.

November's assurances came after Nortel had announced a US$3.4 billion loss. With Wednesday's filing for Chapter 11 protection in the United States, Canada and Europe, the longevity of the deal is again called into question.

"Bankruptcy does not mean going out of business, but Nortel is fighting for its life," says Zeus Kerravala, an analyst with the Yankee Group.

From the partnership perspective, Kerravala says bankruptcy makes it harder to get things done. "If I am Microsoft and I want to get Nortel to invest in creating a new product is that still a viable option?"