Mitchell Klipper, CEO of Barnes & Noble's retail group, which includes its bookstores but not its Nook unit, sold about 67 percent of his shares of the company, according to an SEC filing late Monday.

Klipper sold a total of about 400,996 shares for between $13.99 and $14.53 per share.

He had about 598,371 shares as of July 17, according to FactSet, equivalent to a 1 percent stake in the company.

Barnes & Noble is in a transition period following the departure of CEO William Lynch. It is reviewing its strategy related to its Nook e-book readers, which it invested heavily in as consumers increasingly turn online to buy books.

In its most recent quarter, its net loss nearly doubled and revenue fell nearly 9 percent to $1.33 billion.

Barnes & Noble's shares fell 22 cents to $14.10 in Tuesday morning trading after going as low as $13.84.