Western Digital Corp. (Nasdaq: WDC) is set to buy flash storage company Virident Systems for roughly $685 million in cash.

The Irvine, Calif.-based buyer facilitated the deal through subsidiary HGST, previously known as Hitachi Global Storage Technologies, which Western Digital bought in March 2012. HGST develops advanced hard disk drives and various data storage devices.

The Milipitas, Calif.-based computer systems company, since being founded in 2006, has raised $104 million in venture capital from Artiman Ventures, Cisco Systems Inc. (Nasdaq: CSCO), Globespan Capital Partners, Mitsui Global Investments, Seagate Technology plc and Sequoia Capital.

In recent months, Western Digital has been looking to expand in the storage services sector via M&A. In July, the company purchased Lincoln, Mass.-based VeloBit, a developer of storage-optimization software. Before that, the company picked up Stec Inc., a Santa Ana, Calif.-based manufacturer of custom memory devices, for $320.8 million.

The Virident deal is expected to close in the fourth quarter of this year.

RBC Capital Markets advised Western Digital on the purchase. Virident tapped Bank of America Merrill Lynch (NYSE: BAC) to run the sale process.