Quarterly revenues within the global optical networking sector were down year-on-year for the first three months of 2012, according to Ovum.
This is the first time there has been an annual fall in revenues for almost two years, as sales in Europe fell by more than is typical sequentially.
Alcatel-Lucent posted its worst global quarterly results since 2005, while there was a nine percent fall overall from the same period of last year.
Sales underperformed across all regions and annualised spending declined by €237 million, or two percent sequentially, which wiped out a third of the progress made last year.
"Preliminary results for 1Q12 indicate more a cause for concern than a cause for panic," said Dana Cooperson, practice leader of Ovum's network infrastructure practice.
She explained that although first quarter sales were lower than sales in the closing three months of 2011, actual spending surpassed an €11.8 billion forecast. Meanwhile, results in the Asia-Pacific region and Europe were less negative than earlier predictions had suggested.
Ovum said the early 2012 blip could have been caused by the difficult times forecast for the end of last year simply arriving a few months late.
It believes the late show is mainly due to the current macro-economic and political challenges in Europe.