Samsung sent a letter to SanDisk’s Board of Directors this week that sought to reiterate its willingness to acquire SanDisk for $26 per share in cash. SanDisk notified Samsung that its Board of Directors had unanimously turned the purchase offer down.

In a letter, Samsung said that it was deeply disappointed in SanDisk’s rejection. Samsung said that over the four months of discussions in both Seoul and San Francisco, SanDisk continued to cling to its unrealistic expectations.

Samsung reiterated in its letter than it still wants to purchase SanDisk for $26 per share amounting to $5.8 billion in cash. SanDisk for its part maintains that the Samsung offer grossly undervalues the company and represents a discount of 55% when viewed against the 52-week high trading price for SanDisk stock.

Samsung, on the other hand, maintains that its $26 offer, representing a 93% premium over SanDisk's closing price on September 4, is more than fair. SanDisk's letter to Samsung stated that when talks first began with Samsung on May 22, Samsung had said it might be willing to pay a significant premium to the 52-week high trading price.

Samsung is very eager to acquire SanDisk for several reasons according to the Wall Street Journal. The purchase would eliminate the approximately $354 million per year Samsung pays SanDisk in licensing fees and royalties.

The purchase would also possibly allow Samsung to cut NAND production costs, a contributing factor to the performance woes of the NAND industry overall. The purchase would also give Samsung a much larger retail outlet for its NAND chips in devices like flash drives, media players, and SSDs.

The Wall Street Journal reports that any deal that SanDisk and Samsung found acceptable among themselves would face significant scrutiny from regulators in the U.S. and Europe. Samsung accounts for about 27% of NAND production and SanDisk accounts for about 17% of the production. A combination of the two firms could raise significant concerns.