The Chief Financial Officer (CFO) of Mobile Streams, a telecommunications group, has resigned less than a week after the company issued a profit warning.Gaston Cerf resigned with immediate effect and the search for his replacement has begun, the company said. On January 29th the group issued a profit warning stating revenue for the six months ended December 31st climbed to around £27m from £23.7m in the comparative period a year earlier, up 14% in sterling and 28% in pesos.However, the increased revenue was insufficient to offset both higher marketing expenditures and adverse currency movements, and as such the group anticipates a reduction in earnings before interest, tax, depreciation and amortisation (EBITDA) for the full-year.Simon Buckingham, Chief Executive Officer, said: "Gaston has done a solid job for Mobile Streams during a difficult and complex period as we managed the challenges created by the financial issues in Argentina."As of 14:58 the share price dropped 18% to 25p.WS