Senior vice president Christopher J Baldwin said in a statement: "Our primary business objective is to win in the market place. As we implement this pricing action we will work with our customers to create programs which will drive retail takeway. "Given the mid-year timing of this pricing action and our commitment to planned consumer and customer promotions and merchandising events, we expect minimal financial impact from the pricing in 2007." Hershey's struggle against mounting production costs means a third of the confectionery giant's brands will see a 4-5 per cent rise in price. Brands affected include Reese's, Hershey's Kisses and Twizzlers. The increase came into force on Wednesday for all domestic, wholesale, standard, king-size and vending lines. The company is hoping the move will deter cost pressures from raw and packaging materials, fuel, utilities and transportation from impacting on full year results. Last month, Hershey said it expected full-year net sales growth of 3-4 per cent. Competitor Mars has already raised prices in the US, with Snickers, Twix and other brands increasing by 5 per cent and Wrigley will soon follow with an expected 10 per cent price hike expected later this year.