"In refining you cannot beat having an experienced team to lift your performance. This was roundly demonstrated in the first half of the year by the processing fee revenue produced, which at $170.9 million was $2.5 million better than for the whole of 2014," Mr Post said.
"The combination of debt reduction and the continued progress on the construction of the $365 million Te Mahi Hou means that the company will pay a dividend to shareholders for the first time in two years."
He said credit for the positive result goes to the 500-strong team at Marsden Pt.
But a union representing workers at the site is questioning whether a proposed 0.5 per cent pay rise is all the company can afford.
"Despite announcing a healthy half-year result, the Marsden Pt bargaining team is only offering workers a miserly 0.5 per cent pay rise," First Union organiser Jared Abbott said.
"In difficult years the workers have willingly accepted wage freezes, but after the workers lifted the company back into profit they're only being offered an extra 0.5 per cent, even though the CEO's remuneration package kept rising in the good years and the bad.
"It is an insult to the local workers who have worked excessive overtime to keep the refinery profitable. In light of its net profit after tax of $65 million, the company can afford to lift wages."
But Refining NZ spokesman Greg McNeill said the company was disappointed the union had chosen to talk publicly when both parties were still around the negotiating table.
"From our viewpoint, discussions with the union have been progressing well and our team will continue to negotiate with the union in good faith," he said.