. subject to certain exceptions , including purchases from sabanci holding and its subsidiaries , citigroup has otherwise agreed not to increase its percentage ownership in akbank . other items sale of mastercard shares in 2007 , the company recorded a $ 367 million after-tax gain ( $ 581 million pretax ) on the sale of approximately 4.9 million mastercard class b shares that had been received by citigroup as a part of the mastercard initial public offering completed in june 2006