* New contracts to be available for trade on Dec. 7

* Two largest oil futures exchanges to list sour crude

LONDON, Nov 11 (Reuters) - IntercontinentalExchange (ICE) (ICE.N: Quote, Profile, Research) will list two cash settled futures contracts tracking Argus Media's sour crude index in early December, it said on Wednesday.

The most widely traded crude oil at present, used as the global benchmark, is light and sweet -- meaning it has a low sulphur content. Sour crude, like most of the oil produced by Saudi Arabia, contains more sulphur.

Sour crude output and demand are rising.

ICE's announcement follows Saudi Arabia's decision to switch to the sour crude index as the benchmark price for all grades of its crude oil sold to the United States.

The world's two largest oil exchanges, ICE and NYMEX, will now list sour crude contracts.

"The new futures contracts are the ICE Argus Sour Crude Index (ASCI) Future, which is an outright contract, and the ICE Argus Sour Crude Index (ASCI) Differential Future, which is the differential between the ASCI and the West Texas Intermediate (WTI) price," the exchange said in a statement.

WTI is sweet crude used as a benchmark and is deliverable to the current light sweet crude oil futures contract CLc1 on the CME Group New York Mercantile Exchange (NYMEX).