MOSCOW, July 12 (Reuters) - The Russian rouble weakened slightly against the dollar on Friday while trading volumes remained low.

Sanctions on Moscow Exchange MOEX.MM and its clearing agent, the National Clearing Centre (NCC), led to a range of varying prices and spreads as trading shifted to the over-the-counter (OTC) market on June 14, obscuring access to reliable pricing for the Russian currency.

Central bank data published on Thursday showed Russia's foreign trade surplus rising 19% year-on-year to $67.8 billion in the first half of 2024. The regulator noted a "more significant decrease in imports than in exports".

The rouble climbed to one-year highs in mid-June.

The central bank has singled out foreign trade operations as the most important factor influencing the rouble exchange rate. The Russian currency is still buttressed by capital controls and state foreign currency sales.

Against the yuan, which had already become the most traded foreign currency in Moscow before the latest sanctions were imposed, the rouble weakened by 0.1% to 11.97, according to an analysis of the OTC market.

It was down 0.7% at 95.18 against the euro.

Brent crude oil, a global benchmark for Russia's main export, was up 0.5% at $85.91 a barrel, amid signs of easing inflationary pressures in the United States, the world's biggest oil consumer. (Reporting by Gleb Bryanski; Editing by Toby Chopra)