* Q4 core earnings beat expectations
* Expects gradual improvement in refining margins in 2014
* Margins to be boosted by Libya, Iran
MILAN, Feb 21 (Reuters) - Italy's Saras said on Friday its refining business should get a boost if its partner Rosneft goes through with plans to buy part of the oil-trading operations of Morgan Stanley.
Saras, controlled by the Italian Moratti family, runs the Sarroch refinery in Sardinia. It is partly owned by Rosneft, Russia's state-controlled oil giant, with which it has a joint venture for trading and processing crude oil and selling refined products.
Last December, Rosneft agreed to buy much of Morgan Stanley's physical oil-trading business. In November, Rosneft head Igor Sechin said the group was looking to raise its stake in Saras.
In a statement on 2013 results, Saras said improvement in its refinery business helped its core earnings rise more than threefold in the fourth quarter, to 64.4 million euros from 17.6 million euros a year before. The result topped an analysts' consensus forecast provided by the company of 21 million euros.
"These were much better than we expected," a Milan-based analyst said.
Chairman Gian Marco Moratti also said the company expected a gradual improvement in refining margins this year as Libyan crude production recovers and sanctions against Iran are eased.
The Italian refiner imported sweet Iranian crude before the U.S-led embargo was imposed. It was also a big buyer of Libyan crude before conflict interrupted supplies there.
A recovery in economic growth and demand for petrol products would also bolster refining margins, Moratti said.
European refining margins remain under pressure because of over-capacity and increased competition from the Middle East and Asia. Declining local demand and older and less-efficient plant in Europe has also held back growth.
At 1338 GMT, Saras shares were up 2.2 percent while the European oil and gas sector was up 0.67 percent.