BNN Bloomberg is Canada’s definitive source for business news dedicated exclusively to helping Canadians invest and build their businesses. BANGKOK — Oil prices surged Tuesday as fighting intensified in the Middle East, while world shares were mixed after markets in Tokyo and Seoul rebounded from early losses. The price of Brent crude climbed 4.1 per cent to US$86.73 a barrel after soaring nearly 10 per cent on Monday. U.S. benchmark crude was up 3.1 per cent at $80.55 a barrel.Oil prices are still below their wartime peak of nearly $120 a barrel, but uncertainty over the future stability of supplies…