Cloud security firm Skyhigh Networks has raised $40m in its latest funding round from investors Greylock Partners and Sequoia Capital, bringing its overall funding to $66.5m.

The California-based startup, whose 200 customers include Cisco, Equinix and DirecTV, is on a mission to make it safer for enterprises to buy software as a cloud-computing service

Skyhigh is also looking increase its footprint in the cloud security market, expand internationally and develop new products.

Rajiv Gupta, CEO of Skyhigh Networks, said: "With this funding we will expand sales and double down on product innovation to continue to deliver the industry’s most comprehensive, effective, and easy-to-consume cloud security offering."

The latest funding round, which was also led by Salesforce, comes as an increasing number companies start to access applications via the web and ensure that the software is secure.

Skyhigh, which has 133 employees, makes software for companies that allow them to monitor employees’ use of cloud computing services.