The Star urgently shuts down all pokie machines in Sydney, Gold Coast and Brisbane

Star Entertainment Group said on Monday its systems have been disrupted by performance issues, resulting in the shutdown of all electronic gaming machines and electronic table games at three of its casinos.

The casino operator said system performance issues were identified during testing after planned upgrades to introduce cashless gaming.

The company is working with its external provider to address the issues, it said.

'Treasury Brisbane, The Star Gold Coast and The Star Sydney remain open with table games,' it said.

Last month, Star Entertainment appointed Steve McCann as its CEO and managing director to lead the firm out of a regulator inquiry into its Sydney operations that had triggered a management exodus in recent months.