Westland Milk Products said it processed 5.3 per cent more milk in the season just ended, compared with the previous season, in spite of the area being hit by drought early in the year.
This compares with a 2 per cent drop in the total New Zealand milk production for 2012/13.
Chief executive Rod Quin said Westland, New Zealand's second biggest dairy cooperative after Fonterra, processed nearly 670 million litres of milk over the 2012/13 season, most of which is processed into various powder-based products for export.
Changes at Westland's Hokitika factory allowed milk processing all year round, without the traditional shut-down period.
Despite the West Coast being severely impacted by a drought this season, Quin said West Coast suppliers held their own, keeping production to much the same levels as last year.