Activist hedge fund Oasis Management has ramped up the pressure on Wagamama owner The Restaurant Group to overhaul its business strategy by penning an open letter outlining its concerns, according to a report by The Independent.

Activist hedge fund Oasis Management has ramped up the pressure on Wagamama owner The Restaurant Group (TRG) to overhaul its business strategy by penning an open letter outlining its concerns, according to a report by The Independent.

Hong Kong-based Oasis, which holds a 6.5% stake in the business, said it decided to go public after a private approach suggesting reforms was rebuffed.

Shares in TRG, which also owns the Frankie & Benny's chain of American-Italian restaurants, have fallen by nearly two-thirds in the past year although the company did return to profitability in the latest half-year period.

Oasis though, is convinced that major reforms are required saying in the latter that the company has shown "little hope for the future" and urging it to "realign its priorities".

In response, TRG said it is already reviewing the group’s strategic options and feels that it should not be disrupted by an additional process following Oasis’s request.