WPP, the global advertising giant, Friday reported that its 2014 first quarter revenues rose 1.5 percent to 2.57 billion pounds (4.3 billion U.S. dollars), with like-for-like growth of 7.0 percent, driven by the United States and British markets. Revenues for the period were 915 million pounds (1.53 billion U.S. dollars) and 357 million pounds in North America and Britain respectively, said the London-based company. The negative impact of exchange rates on reported revenues stood at minus 8.1 percent in first quarter, reflecting the continuing strength of the pound against many currencies in the final quarter of 2013, said the company. WPP warned earlier this year that currency swings are likely to continue to weigh on the group during the year. The pound increased about 1.5 percent against the U.S. dollar since this year, Bloomberg data showed.