• by Joe Mandese  @mp_joemandese, June 2, 2011

WPP Group, the world's biggest buyer of media, this morning reported a 6.2% gain in its revenues for the first four months of 2010, due largely to improvements in the U.S., the world's largest media marketplace.

Advertising and media investment management continued the strong growth seen in the first quarter, with revenues growing 12% during the first four-months on a constant currency basis.

WPP said its branding and identity, healthcare and specialist communications practices, which include direct, digital and interactive, grew at nearly half that rate, up more than 7%. WPP's public relations and public affairs businesses were up 5%, and its consumer insight revenues grew less than 3% due to a slowdown in demand in the U.S., the U.K. and Japan.