Two US activist investors have attacked The Restaurant Group's £560m takeover of Wagamama, claiming it will "destroy shareholder value". GrizzlyRock Capital and Vivaldi Asset Management, which own almost 2pc of the FTSE 250 company, said they would "unequivocally oppose" the deal. The pair said the acquisition "dramatically weakens the balance sheet". The Restaurant Group, which counts the Frankie & Benny's and Garfunkel's chains among its portfolio, announced terms for a £315m deeply discounted rights issue on Monday. The acquisition and rights issue will be put to the vote at a general meeting on November 28. The company's shares have plummeted in the wake of the deal being announced. Investors have voiced concerns over the deal at a time when Britain's casual dining sector is facing significant headwinds.