The deal valued the British firm at 500 million pounds ($697.85 million), a person familiar with the matter.
Chicago-based BDT will get a non-executive director seat on Brunswick's board as part of the deal and Brunswick plans to set aside 18 million pounds for a cash distribution to members of the company, the memo said.
Brunswick will also distribute 140 million pounds to partners in the company, the memo said, adding that the founders are selling some of their shares to BDT.
It is also changing its corporate structure from a limited liability partnership to a private company, the memo said.
The Financial Times first reported the news.
($1 = 0.7165 pounds)
(Reporting by Shariq Khan in Bengaluru; Editing by Arun Koyyur)