However, managing director Grant King is still not confident his company will achieve a total takeover of New Zealand’s Contact Energy.

"Looking further ahead, the progress on major development projects, the acquisition of Contact Energy ... should continue to deliver growth in earnings averaging 10-15 percent per annum over the coming years," Reuters reports King as telling Origin’s annual meeting in Melbourne on Wednesday.

However, King said he still did not expect Contact's remaining shareholders to take up Origin’s offer to buy the balance of the company.

Origin in July bought Edison Mission Energy’s 51.2% interest in Contact Energy for NZ$1,675 million, or NZ$5.67 per share, and later, as required under New Zealand takeover laws, offered the same deal to Contact’s 105,000 minority shareholders.

King has previously said he would be content with Origin only holding a 51.2% controlling stake in Contact and last month Contact’s independent directors recommended small stakeholders reject Origin’s offer which expires next Tuesday.

King, who said Origin's performance in the first quarter was in line with expectations, added that the Perth Basin in Western Australia was expected to be a major contributor to earnings over the next few years.

In the June year, oil production from the basin's Hovea, Eremia and Jingemia fields averaged more than 6700 barrels of oil per day - a 300% increase on the previous year. That average daily production was expected to increase to almost 10,000 bopd as Jingemia-4 was fully commissioned and the Hovea field further developed.

Origin’s focus has been primarily on gas, with only 16% of its petroleum output in oil and condensate.