Manufacturers are showing keen interest in a prospective new supply of gas for the energy-starved Victorian market, said Amplitude Energy chief executive Jane Norman, who unveiled a $400 million-plus investment in the state.

Norman said Amplitude and its cashed-up Israeli partner OG Energy are planning a drilling and development campaign off the Victorian coast targeting enough gas to power more than 600,000 homes in the state, which could delay the onset of gas shortages during peak winter demand.