LONDON : Oil prices were mixed on Friday following recent volatility and as investors awaited the final outcome of an EU summit on tackling its debt crisis, traders said. Brent North Sea crude for delivery in December rose 40 cents to $112.82 a barrel approaching midday in London. New York's main contract, light sweet crude for November, dipped two cents to $92.08 a barrel. "The oil market continues to be beset with considerable uncertainty, as evidenced by unusual price fluctuations," said Commerzbank analyst Carsten Fritsch.