With backing from Chinese tech group Unisplendour, Western Digital Corp. said Wednesday that it would pay $19 billion to purchase flash storage company SanDisk Corp, reports The Deal's Chris Nolter. The payout comes to $86.50 per share in cash and stock, with the composition of the bid dependent upon Western Digital closing a nearly $3.8 billion equity investment from Unisplendour. If Western Digital collects Unisplendour's investment, the Irvine, Calif., memory company will pay $85.10 per share in cash and 0.0176 shares of its common stock per share of SanDisk. If the Unisplendour investment has not closed, the composition is $67.50 in cash and 0.2387 shares of Western Digital stock. SanDisk has been on The Deal's Activist Watch List since spring, after the maker of flash memory drives for phones, cameras, thumb drives and other devices slashed guidance. Western Digital CEO Steve Milligan said that adding SanDisk's strength in flash memory would add to the buyer's leading positions in storage. Milligan will maintain his post at the post-merger company. SanDisk CEO Sanjay Mehrotra will join the board.