BUZZ-Rentrak Corp: Stock hits record high after WPP takes stake
** Viewership rating provider's shares rise as much as 16.9 pct to a record high of $75.39
** Advertising giant WPP Plc (LSE: WPP.L - news) to buy a 16.7 percent stake in the company for $56 million
** Rentrak to buy WPP unit Kantar Media business's U.S. television measurement business for $98 million in stock, which is worth about 12.4 pct of its total shares outstanding
** Deal is expected to add about $7 million to $9 million to Rentrak's revenue in fiscal 2016
** Stock is among the top percentage gainers on Nasdaq
** Up to Wednesday's close, stock had risen about 70 pct this year (Reuters Messaging: arathys.nair.thomsonreuters.com@reuters.net)