The Uruguay-based miner produced 18,401 ounces of gold in the three months to end February, up 35% on a year ago.
Cash costs also fell, to US$999 per ounce, from US$1,104, though costs are still higher for the nine months of the year so far.
Revenues in the latest quarter rose by 15% to US$30mln, though net profit eased to US$3.5mln from US$5mln after a jump in costs of sales during the period.
Orosur said the improvement in production and cash cost was in line with expectations despite operational issues in the open pits at the San Gregorio mine that have yet to be fully resolved.
First ore from the Arenal Deeps development is targeted for April following completion of the ramp.
Production for the full year remains on track to hit its 63,000 to 68,000 ounces target and will reflect stronger production from Arenal as higher grade ore comes on stream.
Ignacio Salazar, interim managing director, said: "In this quarter, the company has completed the ramp at Arenal Deeps, production and costs have been brought in line with expectations, we have identified high priority drill targets at Anillo to start drilling in May and have been re-evaluating Quebrada Pantanillo as a high sulfidation gold system to improve the economics of the project."
Salazar took over on an interim basis following the resignation of chief executive David Fowler in March.
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