ADT Inc. and Britain’s Hawley Group Ltd....

ADT Inc. and Britain’s Hawley Group Ltd. have agreed to merge in a $52-a-share buyout offer valued at about $715 million. The bid, announced Friday, surpasses the $47-a-share offer Hawley Group made Aug. 17. ADT is one of the world’s largest suppliers of electronic security systems; if the merger is completed, it would make the British company a major part of the U.S. central alarm systems business.