US ethylene December contracts were heard to be settling 2 cents above November's level, increasing the net transaction to 48.25 cents/lb ($1,063/mt), sources said Monday.
The posted price for December also would settle up 2 cents to 52.75 cents/lb ($1,163/mt), according to Platts data.
If the December contract prices are accepted marketwide, both settlements would be at their highest since September 2012 prices, which were at the same levels.
The increase surprised some market participants that expected a price hike in the range of 1-1.50 cents/lb, as spot prices reached a six-month high of 59-59.25 cents/lb FD USG on December 30, according to Platts data.
US spot ethylene assessment averaged 57.08 cents/lb in December, up 4.03 cents from November's average of 53.05 cents/lb, Platts data showed.
US purity ethane averaged 27.97 cents/gal, an increase of 3.09 cents, while Non-LST Mont Belvieu propane prices averaged $1.2748 cents/gal in December, up 9.41 cents from November's $1.1807 cents/gal.
US ethylene contract prices are settled between major producers and buyers at the beginning of the month for the previous month. The settlements take into consideration changes in spot ethylene and spot feedstock pricing.
In spot markets Monday, January ethylene was heard bid at 55.75 cents/lb Mont Belvieu Williams pipeline basis and offered at 57-58 cents/lb Mont Belvieu Williams pipeline basis. February spot ethylene was heard offered at 58 cents/lb Mont Belvieu Williams pipeline basis, while March was heard traded at 57.50 cents/lb Mont Belvieu Williams pipeline.
