NatWest's shares slid Monday after the company announced a £2.7 billion ($3.7 billion) deal to acquire one of the U.K.'s largest wealth managers.

First major acquisition since full return to private hands last year will come as high street banks seek to diversify

NatWest's shares slid Monday after the company announced a £2.7 billion ($3.7 billion) deal to acquire one of the U.K.'s largest wealth managers.