In what was very likely its final quarterly earnings report as a public company, Tellabs missed analysts' revenue estimates for the third quarter by a wide margin, and showed further evidence that it is losing traction with long-standing customer Verizon Communications.

Separately, Marlin Equity Partners , which two weeks ago announced it was acquiring Tellabs Inc. (Nasdaq: TLAB; Frankfurt: BTLA) for $891 million, said it has commenced its tender offer for all outstanding shares of Tellabs at $2.45 per share. The tender offer expires on Dec. 2. The Tellabs board has already approved the sale of the company. (See: Tellabs to Be Sold to Marlin for $891M and Tellabs' Last Hope: Marlin's Optical Ambition.)

Having previously canceled its quarterly earnings call, Tellabs announced its third-quarter earnings via a 10Q filing with the SEC.

Revenue for the quarter came in at $198.5 million, well under the $212 million estimate of MKM Partners, according to Michael Genovese, communications equipment analyst at MKM. The revenue posting also represented a significant drop from the $264.4 million in revenue Tellabs posted for the same period last year. The vendor saw its net loss grow to $9.8 million, from $3.9 million in the third quarter last year.

Its optical sector revenue was $88.4 million, down about $20 million from the third quarter of 2012, and Genovese said in a research note after the filing that he believes the sales shrinkage in optical is connected to Tellabs losing metro optical business at Verizon to competitors such as Ciena, the vendor's one-time, would-be merger partner.

— Dan O'Shea, Managing Editor, Light Reading