Napa Valley has become the first viticulture area to be awarded a US certification mark, according to trade group Napa Valley Vintners (NVV).

The mark, issued by the US Patent & Trademark Office, is intended to protect the reputation of the area and "prevent consumer deception". The NVV said the process took five years to complete. 

J Scott Gerien, trademark attorney for Dickenson, Peatman & Fogarty - NVV's counsel - said: "Working with other countries to obtain protection for the Napa Valley name, it became clear we needed similar status here at home to be taken seriously when requesting support outside the US."

To register the certification mark, the NVV obtained around 100 agreements from wineries and wine-related businesses that use the word "Napa" in their own trademarks, to prove they were compliant with the standards for the Napa Valley American Viticultural Area (AVA).

The NVV has gained name protection status for the Napa Valley in Australia, Brazil, Canada, China, the European Union, India, Israel, New Zealand, Norway, Taiwan, Thailand and Turkey. The organisation said that its new US designation will allow  it to "negotiate with additional countries and further its goal of protecting consumers worldwide".

Earlier this year, the president of Jamieson Ranch Vineyards in Napa Valley acquired the Californian wine producer from parent company Madison Vineyard Holdings.