The country's second largest oil and gas producer Santos has cut 100 jobs from its South Australian operations.
Redundancies will begin in the first quarter of 2013.
Those affected are based in the company's Adelaide head office and its Moomba operations in the Cooper Basin.
Santos said the affected roles were not going to meet the needs of the business in the coming years.
Those needs include the next stage of its natural gas development in the Cooper Basin, based around in-fill drilling and shale gas.
Santos vice president James Baulderstone said the decision was made as part of a broader program to ensure the eastern Australia business remains cost competitive.
"In order to execute an ongoing successful natural gas development program in the Cooper Basin, we need to ensure that our practices are efficient, and our business model is a competitive one," he said in a statement.
The changes were necessary if Santos was to continue to be a competitive, global company that can benefit the local community, Mr Baulderstone said.
The company's South Australian workforce currently consists of 1,600 employees, out of a national workforce of 3,200 people.
The company's chief executive David Knox said in an interview last week that it would need to bring its cost base down.
Santos shares were up down 11 cents at $10.95 on Wednesday.