PEDAL POWER: Society of Beer Advocates committee member Martin Bilmer is among those against DB's trademarking of the term Radler.

A beer drinkers' society warns it faces bankruptcy if it loses its dispute with DB Breweries over a shandy-like lager which most of its members do not drink.

The Society of Beer Advocates (Soba), an organisation with about 500 members run by volunteers, has taken legal action against DB over the term "Radler", which the brewing giant uses on a citrus-flavoured brand of Monteith's.

DB has a trademark over Radler which Soba is attempting to have declared invalid, arguing that like pilsner or lager, the term is a generic name for a recognised style of beer over which no-one should have exclusive rights.

Last week, DB's lawyers, Simpson Grierson, wrote to Soba urging it to drop the action, hinting strongly that it would pursue Soba for its costs if it won the case.

"The evidence is compelling," Earl Gray, a partner at Simpson Grierson wrote to Soba's lawyers, James & Wells. "Your client's costs will continue to grow. Accordingly, we invite your client to withdraw each of its applications without delay."

The society found the letter "intimidatory", treasurer Robert Owen said, but resolved to continue the fight at its annual general meeting last week, believing it can win the case.

Radler, German for cyclist, was developed as a drink in Bavaria in the 1920s, and while the exact recipe is uncertain, it was a beer and soda mix aimed at cyclists because of its lower alcohol content.

If DB is allowed sole use of the term Radler, Soba argues, it may attempt to trademark others, preventing New Zealand's growing craft beer industry from using them.

Mr Owen said it was unlikely that Radler was among the favourites of its members, who generally preferred fuller flavoured beverages.

"No, probably not. It's basically a shandy," he said.

"But this is a point of principle; we're not defending a style of beer that's one of our favourites but it's important because it is a style of beer and if we let this one go, then there's no reason why they won't try to take others."

DB has already forced Dunedin brewery Greenman to drop its use of the term Radler, prompting Soba to pursue the issue. It has also challenged DB's use of "Saison", and DB dropped its Saison trademark shortly afterwards.

Soba – deliberately named to be ironic – says it does not have the resources to cover a large legal bill. Its lawyers estimate the bill so far to be between $5000 and $6000.

A spokeswoman for DB said the costs it had incurred in the dispute were "substantial".

Mr Owen said: "We don't have the money in the bank, we would have to go into liquidation."

A spokeswoman for DB said its application to trademark the term in 2003 was not contested.

DB does not claim to have come up with the term, acknowledging the German origins on its website, but bases its right to trademark it on the lack of public awareness of the origins, and the "considerable" investment in the brand.

The spokeswoman said DB looked forward to the 18-month dispute being resolved.

"We are confident our trademark registration will be upheld," she said.