Kuwait's Zain has ruled out plans to book an impairment in the third quarter for its key Sudan unit, after the Sudanese pound was devalued by 40% in a move that cuts the dollar value of the subsidiary's earnings, Reuters has reported. "Q3 2012 will show the full impact of the currency devaluation," Zain said. "However, we believe that we will not experience any impairment of the investment." Zain Sudan accounted for a third of the group's 40.3 million customers at March 31. It made a first-quarter net profit of $51.3m, about a fifth of the group total.