The cash deal, pitched at 850 pence per share, is worth £2.7 billion ($3.3 billion, 3.0 billion euros) or £4.6 billion including debt, Greene King said in a statement.
The announcement, which represents a 51-percent premium to Friday's close, also catapulted shares 51 percent higher to finish at 850 pence - matching the agreed price.
Greene King, which is listed on the London stock market, has roughly 2,700 pubs, restaurants and hotels dotted across Britain. It employs more than 38,000 staff.