BEIJING, June 29 - China unexpectedly increased gasoline and diesel prices on Monday, raising them for the third time since late March to their highest level ever.

At nearly 9 and 10 per cent respectively for gasoline and diesel, the increases are the biggest since a shock rise up to 18 per cent exactly a year ago -- a move that helped pull oil prices off record highs as traders feared that higher fuel costs could slow demand growth in the world’s second-largest consumer.