Extreme Networks, which has a fast-growing operation in the Triangle where its engineering operations are based, says it is buying Enterasys Networks in a deal that will double its annual revenues to more than $600 million.

The deal worth some $180 million was announced early Thursday.

Enterasys is based in Salem, New Hampshire, and has annual revenues of some $330 million.

Extreme Networks (Nasdaq: EXTR), which is based in San Jose, Calif., says the deal once closed will make it one of the top four networking services providers.

Both firms focus on high performance networking with an emphasis on enterprise networks, data centers and “cloud computing.”

“Combining Enterasys technologies and products including their Coreflow modular switches, IdentiFi wireless and the NetSight system management application will extend and complement our product offering which we expect will provide significant added value to the current customers of both Extreme and Enterasys,” said Extreme’s CEO Chuck Berger.

Extreme said the deal is expected to be “immediately accretive” to earnings.

Enterasys, which is privately held, has some 900 employees. 

The deal is expected to close in the fourth quarter.

Extreme currently has more than 6,000 customers spread across more than 50 countries.