company, Britain's WPP Group PLC announced Friday that it is buying US heavyweight Young and Rubicam Inc. for $4.7 billion in stock.

WPP, which owns Ogilvy and Mather Worldwide and J. Walter Thompson (which holds the Bermuda Tourism account), said the acquisition would greatly expand its client base and generate annual savings of more than $30 million. The two advertising powerhouses already share a number of major customers, including Ford Motor Co., Mattel Inc., Kraft Foods and Sears, Roebuck and Co.

The announcement brings to a climax several months of fitful takeover talks.

The deal offers Young and Rubicam shareholders a choice of either 0.835 new WPP American Depositary Receipts or 4.175 new WPP shares for each Y and R share. The transaction amounts to $53.02 for each common share in the US company, based on Thursday's closing price for a WPP ADR of $63.50.