WaveDivision Holdings has completed its $50 million acquisition of Bellingham-based Black Rock Cable.

WaveDivision, a Kirkland business-class fiber optic and broadband service company, announced plans to purchase Black Rock in September. Black Rock provides high-speed fiber optic services in Whatcom, Skagit and Snohomish counties.

Wave provides video, Internet and phone services for nearly 400,000 residential and commercial customers in Washington, Oregon and California.

Wave CEO Steve Weed said the acquisition extends Wave's dark fiber network from the Canadian border to San Francisco.

"Connecting the Wave network to Black Rock's thousands of miles of fiber infrastructure adds to Wave's already asset-rich, high-capacity business and stands to enable better services for both new and existing customers," Weed said in a news release.

The company says the transaction, which closed at the end of 2012, will not impact Black Rock customers or employees. Services will continue without interruption as operations continue to be merged with Wave.

Reach Business Editor Dave Gallagher at 360-715-2269 or dave.gallagher@bellinghamherald.com. Read his business blog at blogs.bellinghamherald.com/business or follow him on Twitter at @bhamheraldbiz.