EU "bullying" could put Britons off foreign drink, says UK pub boss

* Pubs group says sales growth slowing, costs rising

* Warns against 'bullying' approach from European leaders

* Says needs to agree tariff-free trade with European suppliers

* Shares (Berlin: DI6.BE - news) fall to three-month lows (Recasts, add analyst reaction)

By Rahul B and Paul Sandle

LONDON, Nov 2 (Reuters) - A "bullying" approach by European leaders over Brexit risks hurting sales of French wine, German beer and Swedish cider, said the founder of British pubs chain JD Wetherspoon, a prominent "Leave" campaigner.

The warning came as the group, which operates more than 900 pubs, said strong sales growth in the summer had slowed in recent weeks, and it faced rising costs, sending its shares lower on Wednesday.

Company chairman Tim Martin said a call from European Commission President Jean-Claude Juncker last month for a firm stance in Brexit talks could backfire.

"If we, and companies like ours, are unable to agree on tariff-free transactions, it will inevitably result in a loss of business for European companies which have done nothing to deserve this outcome," he said, using a company trading statement to make his point.

"Indeed, the ultimate sanction will be in the hands of UK consumers, should they take offence at the hectoring and bullying approach of Juncker and co. French wine, Champagne and spirits, German beer and Swedish cider, for example, are all at extreme risk."

The group said it normally agrees on trade deals with suppliers for between three and 10 years.

Like other British businesses, it faces higher import prices following the slide in the value of the pound after Britons voted in June to leave the European Union. Sterling has lost around 15 percent against the euro since the referendum.

Martin was a high-profile backer of Britain's bid to leave the EU, appearing in television debates before the June 23 vote and the company distributed half a million beer mats challenging statistics used by the government to back the "Remain" campaign.

Shares in the group fell to three-month lows after the trading update. They were down 6.1 percent at 833.5 pence at 1030 GMT.

"The company anticipates higher costs in the remainder of the current year, for instance in the areas of wages, business rates and repairs," Martin said. The company's financial year runs until July 30.

Wetherspoon said sales growth slowed to 2.3 percent in the last five weeks of the period ended Oct (HKSE: 3366-OL.HK - news) . 23, compared with growth of 3.5 percent for the 13 weeks ending at the same point.

The company said it had made a reasonable start to the current financial but added that any full-year forecasts were "inevitably tentative".

Rivals Greene King Plc and Marston's Plc have reported a slowdown in like-for-like sales in their latest trading updates. (Reporting by Rahul B in Bengaluru and Paul Sandle; editing by Keith Weir)