Price of the Kuwaiti crude oil increased to USD 107.28 per barrel on Wednesday, said the Kuwait Petroleum Corporation (KPC) on Thursday.The climb came as G-20 states\' leaders prepared to gather in France, after Greek Prime Minister George Papandreou tried to calm markets with his statement that the second referendum plan would emphasize the continued membership of Greece in the euro zone.Greece\'s announcement about its plan to hold public referendum about the European financial salvage scheme sent negative ripples across the European financial and stock markets, pushing the main indices down.Meanwhile, the prices of oil, currently, are unstable due to sluggishness in the US industrial sector, amid renewed fears that Greece may declare bankruptcy and failure to pay due debts.OPEC had declared that the price of its 12-crude basket dropped 77 cents putting the level at USD 106.35 per barrel, on Tuesday, compared to USD 107.12 pb on Monday.Member states of the cartel decided, in the middle of June, to maintain the ceiling of the production at 24.580 million per day because of a glut on the international markets. However, they had advised that the markets be kept under close monitoring for three months.