Reuters: The reluctance of big companies to spend at a time of lackluster global growth and fewer major sporting events this year are dampening demand for advertising, said the chief execs of two leading ad agencies. In separate interviews, Martin Sorrell of WPP and Maurice Levy of Publicis sounded cautious about the prospects for the advertising market, citing a lack of vibrancy in the U.S economy, weakness in Brazil, Russia and China, and Europe’s continued fragility. “There is a lot of uncertainty,” said Levy. “Companies have cash to spend but are not in the mood to do so, and consumers are not feeling confident either.”