Nokia Siemens Networks (NSN) has challenged Ciena Corporation's bid for Nortel Networks' optical networking business and submitted a new bid of $810 million in cash for the assets. It earlier lost an auction for the assets to Ciena, which agreed to pay $769 million for Nortel's assets. NSN, along with One Equity Partners LLC, had previously bid $770 million in cash. According to NSN, Nortel would have had to pay Ciena an additional break-up fee of over $20 million to accept that bid because of a prior agreement. As a result, the convertible notes in the Ciena bid should be discounted, making the bid even lower.

The Nortel assets on sale include carrier Ethernet products as well as fibre optics.