Hard drive maker Western Digital has struck a deal to buy flash storage vendor SanDisk for $19 billion, the companies announced today. Subject to a SanDisk shareholder vote and regulatory approval, the merger is expected to close in the third quarter of 2016.

Western Digital said it is seeking to boost its expertise in non-volatile memory, with SanDish's NAND flash giving the buyer "long-term access to solid state technology at lower cost."

Western Digital's WD brand sells the My Book, My Cloud, and My Passport drives to consumers, while the company's HGST subsidiary sells to OEMs and other businesses. SanDisk's flash memory products are sold to consumers, businesses, and device makers. Western Digital pointed out that it and SanDisk have more than 15,000 patents and "complementary product lines, including hard disk drives, solid-state drives, cloud data center storage solutions and flash storage solutions."

SanDisk will continue its longtime joint venture with Toshiba, the merger announcement said.

SanDisk announced its quarterly financial results today, with its revenue of $1.45 billion representing a decline of 17 percent year-over-year. Net income was $133 million, down from $263 million in the same quarter the previous year.

Western Digital reported $3.2 billion of revenue and net income of $220 million in the quarter that ended July 3, down from $3.7 billion and $317 million year-over-year. The company announced preliminary results for the most recent quarter today, with quarterly revenue of $3.4 billion and net income of $283 million. (Full results will be detailed next week.)

While both Western Digital and SanDisk's earnings reports were better than expected, Western Digital's share price dropped on news of the merger and has lost about a third of its value this year, The Wall Street Journal wrote. "Western Digital is facing challenges to its core hard-disk-drive business, which has been under pressure from the success of sales of Apple Inc.’s iPad and other tablet computers that store data on flash-memory chips rather than on magnetic disks," the Journal report said. Buying SanDisk "could be a hedge and a driver of new growth."

Yesterday, we reported that several versions of Western Digital's self-encrypting hard drives are riddled with security flaws that let attackers retrieve data with little effort if they have physical access to the hardware.

For more of our previous reporting on the companies, check out SanDisk’s 128GB microSD card is the biggest, tiniest storage you can buy, SanDisk makes a $60 USB drive with a Lightning connector for your iPhone, HP and SanDisk join forces to finally bring memristor-like tech to market, Western Digital readies first 10TB hard drive, ships new 8TB drive, and Hard disk reliability examined once more: HGST rules, Seagate is alarming.