* 9-month sales volumes up 8.2 pct vs 7.7 pct in poll * Sales revenue down 1.3 pct due to lower cocoa price * Market environment in Europe still challenging (Adds detail, background) By Silke Koltrowitz ZURICH, July 4 (Reuters) - Barry Callebaut BARN.S , the world's biggest maker of chocolate and cocoa products, said strong demand from pastry chefs and restaurants in Europe and Asia helped lift sales volumes by a better-than-expected 8.2 percent in the nine months to May. Its business in austerity-hit Europe also benefits from outsourcing deals -- it struck a deal with Unilever ULVR.L UNc.AS last year under which it supplies chocolate for Magnum ice cream -- helping volumes in its biggest market climb 5.7 percent. "During the third quarter, the company even accelerated its volume growth to 8.9 percent. With this, Barry Callebaut significantly outpaced the global chocolate market, which increased by 1.9 percent," the group said in a statement on Thursday. Volumes sold in the Americas were up 17.1 percent and Asia-Pacific also grew 5.4 percent. The smallest category, products for professionals like pastry chefs, posted strong growth in Europe and Asia-Pacific, Barry Callebaut said. Sales revenue at the group fell 1.3 percent to 3.541 billion Swiss francs ($3.73 billion), in line with an estimate in a Reuters poll, hit by lower raw material prices. ID:nL5N0F81MV Barry Callebaut passes on raw material prices to its customers for about 80 percent of its volumes, meaning its sales revenue is impacted when raw material prices increase or fall. Prices for cocoa beans CCc2 have recovered somewhat from an 11-month low hit in March, with ICE futures CCU3 posting their biggest one-day gain in three months on Wednesday, but are very far from the record-high levels of 2011. Earlier this week, the Zurich-based group confirmed its mid-term financial guidance for 6-8 percent volume growth through 2015/16. By then, it also wants to restore profitability to the level seen before its $860 million buy of Petra Foods' PEFO.SI cocoa unit that made it the world's No.1 in cocoa powder. Barry Callebaut Chief Executive Juergen Steinemann said the group now wanted to focus on integrating the Petra Foods business. Barry Callebaut issued $300 million in new shares and issued a $400 million senior bond last month to help finance the acquisition. ($1 = 0.9490 Swiss francs) (Reporting by Silke Koltrowitz; Editing by David Cowell) ((silke.koltrowitz@thomsonreuters.com)(+41 58 306 7454)(Reuters Messaging: silke.koltrowitz.thomsonreuters.com@reuters.net)) Keywords: BARRY CALLEBAUT RESULTS/