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* Two grades account for one fifth of Libya's production
* Shell, BP and Unipec to take Sarir and Messla grades
* Libya's output is just under 1 million bpd(Adds context and detail)
By Julia Payne and Ahmad Ghaddar
LONDON, Jan 10 (Reuters) - Trading and mining giant Glencorehas lost its exclusive marketing rights for two ofLibya's main crude oil export grades after holding them sincelate 2015, trading sources with direct knowledge said.
The Switzerland-based firm had secured the rights to theSarir and Messla grades when it was one of the few foreigncompanies willing to deal with the North African country duringunrest that has wracked the country since 2011.
Glencore, which had exclusive rights on the two grades untilthe end of 2018, and Libya's National Oil Corp (NOC) declined tocomment.
In a sign of renewed international confidence in Libya's oilindustry, BP and Royal Dutch Shell returned tolifting directly from the country last year, initially takingother grades.
"Glencore lost exclusivity on Messla and Sarir," one of thetrading sources told Reuters, asking not to be named. "Companieslike BP and Shell had their first Messla and Sarir allocation."
A second trader said that now "anyone can get these grades."
The two grades account for nearly a fifth of Libyan outputthat now stands at 953,000 barrels per day (bpd), still wellbelow the pre-conflict level of 1.6 million bpd.
For a period when oil production fell even more sharply,those grades that are exported from the eastern Libyan port ofMarsa el Hariga generated the bulk of state revenues.
Libya's 220,000 barrel-per-day Ras Lanuf refinery, which isnow idled, ran on the two grades.
The remainder of Libya's crude streams have not beenallocated exclusively to one company for such an extendedperiod.
So far, Unipec was also allocated three cargoes from Marsael Hariga in January, one source said, although the proportiontaken of each grade by the trading arm of China's Sinopec wasnot immediately clear.
BP is due to take 1 million barrels on the Crescent Moontanker in mid-January from the same port, according to ashipping source and Refinitiv Eikon ship tracking. BP did notimmediately respond to a request for comment.
Shell is also due to take at least one cargo from Marsa elHariga, three sources said. Shell also did not immediatelyrespond to a request for comment.
Security challenges still threaten Libya's oilinfrastructure. Its largest oilfield, El Sharara, has been shutsince December over a dispute with tribesmen, armed protestersand state guards demanding salaries and development.(Reporting by Julia Payne, Ahmad Ghaddar and Ron BoussoEditing by Jason Neely and Edmund Blair)
