BlackRock Inc. (BLK) on Thursday said it will acquire Barclays Global Investors in a cash and stock deal worth nearly $14 billion, creating a money management giant with more than $2.7 trillion worth of assets under management and a global player that doubles its nearest competitor in size.

BGI, the asset management unit of British bank Barclays PLC (BCS), has long been considered one of the industry's biggest prizes. BlackRock had shown interest in buying the unit six years ago, and negotiations intensified within the past few weeks.

BlackRock will acquire the business in exchanged for $6.6 billion in cash and 37.7 million shares of common stock.

It marks the most aggressive deal that BlackRock has made in its 21-year history, and a turning point in the global asset management industry. "This is a transformational transaction," said BlackRock Chief Executive Laurence Fink during a conference call held late Thursday.

The price represents a substantial premium to what analysts thought BGI would fetch and underscores how capital markets have revived in recent months. It represents a big payday for both Barclays and some of its executives. The firm, renamed BlackRock Global Investors, will have more than $2.7 trillion in assets under management.

-By Joe Bel Bruno, Dow Jones Newswires; 201-938-4047; joe.belbruno@dowjones.com