ST. PAUL, MN -- 3M today reported second-quarter sales at its Electro and Communications business unit were down 4.7% year-over-year on weakness in telecom and consumer electronics.

The unit had sales of $824 million, making up 9% of the company's overall sales. Operating income was $195 million, down 2.3%, while the operating margin was 23.7%.

3M has a large flex circuit board manufacturing operation, which Dr. Hayao Nakahara of NTI Information estimates brought in $180 million in 2011. It is also a leading provider of phototools for PCB fabrication.

For the period, 3M reported net income of $1.2 billion on sales of $7.5 billion, down 1.9% year-over-year. Operating income was $1.7 billion and operating income margins for the quarter were 22.9%. All of the company’s six business segments posted operating income margins greater than 20%.

Organic local-currency sales declined 1.8% in Electro and Communications on weakness in consumer electronics.

3M maintained its full-year 2012 earnings expectations of $6.35 to $6.50 per share. The company anticipates full-year organic local-currency sales growth of 2 to 5%.