(Stuff) - The value of New Zealand wine exports hit a record high in the year to June.

Export values rose 3 per cent to $1.21 billion in the 12 months to June 30, New Zealand Winegrowers has reported.

However, volumes exported fell 5 per cent due to a smaller grape crop in 2012.

This year looks to be better with a record 345,000 tones of grapes harvested so far, 28 per cent more than last year.

"The small 2012 grape crop meant wine was in short supply and wineries took the opportunity to improve their positioning in the market," New Zealand Winegrowers chairman Steve Green said.

"Winemakers have welcomed the more normal 2013 harvest as the improved supply will facilitate renewed export growth in the year ahead," Green said, warning that growers should only make new plantings based on actual demand rather than optimism.

The market still has challenges, he said.

"Supply discipline remains as essential now as ever before. Provided the wine industry learns from the struggles of the past, we can look to the future with confidence."