RABAT (Reuters) - Maroc Telecom reported a 4.3 percent drop in third-quarter operating profit on Thursday as it stepped up investment and commercial efforts to keep subscriber numbers growing, the company said. Operating profit fell to 3.6 billion dirhams while turnover was down 0.6 percent at 7.83 billion dirhams, Morocco's dominant phone company said in a statement. Its client base rose 11 percent to 21.4 million in the year to the end of September. If current market conditions continue without major disturbances, the company should achieve sales of 2 percent and an operating margin of around 45 percent in the full year, it said.