Resources, Energy and Tourism Minister Martin Ferguson said the OPA will make the offshore petroleum legislation easier to understand, and reduce costs for industry and governments.

"However, the new Act does not change any major policies or the current management regime."

While the OPA received Royal Assent on March 29, 2006, it could not be proclaimed to come into effect until all states and the Northern Territory had updated their mirror offshore petroleum legislation, which was completed when Tasmania amended their legislation on June 16 this year.

The largest category of amendments made in the rewrite of the PSLA addresses past drafting omissions, errors and anomalies that have been detected in rewriting the text of the PSLA.

There are also amendments designed to bring provisions that, on account of their age, are out of line with current Australian Government legislative drafting principles into compliance with these principles.

Ferguson added that a number of transitional arrangements were in place for the current regulations under the PSLA to continue in use under the OPA.

"The development of the OPA involved extensive consultation with industry, highlighting just how important the industry sees this legislation," he said.

"I trust the simplification of the Act ensures Australia remains one of the most attractive places in the world to explore for and develop petroleum resources."