Key crude prices in the Middle East have dropped to their weakest level against the Brent benchmark in two months, signaling oversupplied markets as output from both the Middle East and the Americas rises amid tepid demand. The premium of Abu Dhabi’s flagship Murban grade over Brent, the international benchmark, has narrowed in recent weeks and is now at its lowest level since early October, according to estimates by Bloomberg. In Dubai, the discount of the benchmark against Brent had grown to its widest in seven weeks. The Brent-Dubai…