Oasis Management Company, the activist hedge fund firm leading an investor revolt at Wagamama owner The Restaurant Group, has opened a new front in its battle with the company's senior management, claiming TRG has excluded "certain" shareholders from key information ahead of next week's annual meeting.

Oasis Management Company, the activist hedge fund firm leading an investor revolt at Wagamama owner The Restaurant Group (TRG), has upped the stakes in its battle with the company's senior management, claiming TRG has excluded "certain" shareholders from key information ahead of next week's annual meeting.

The report cites a letter written by Oasis to TRG chairman Ken Hanna expressing its "deep concern regarding the equal treatment of shareholders”.

In the letter, Oasis, which holds a 12.3 per cent stake in TRG and has previously taken issue with the company's remuneration packages and general financial performance, claims that ISS, a proxy shareholder advisory group, was made aware of a commitment by TRG to review the remuneration policy, whereas this had “not been (nor has it subsequently been) made public by the company”.