MOSCOW, April 1 (Reuters) - Russia has ordered Kazakhstan's main oil export terminal, which handles crude pumped by U.S. majors Chevron CVX.N and Exxon Mobil XOM.N, to close two of its three moorings amid a standoff between Kazakhstan and OPEC+ over excess production.

The operator of the Caspian Pipeline Consortium (CPC), which exports around 1% of global oil supply via the Russian Black Sea terminal, said late on Monday that the two moorings were halted following snap inspections by Russia's transport watchdog.

The stoppage could more than halve CPC exports if it lasts for longer than a week, trading sources told Reuters.

Kazakhstan has frequently exceeded its production quotas under a pact among OPEC+ producers, which includes the Organization of the Petroleum Exporting Countries and allies, such as Russia.

However, it is finding it difficult to convince the companies operating its largest oilfields to reduce output where they have spent tens of billions of dollars to expand capacity.

Kazakhstan's energy minister stepped down last month after tough discussions on OPEC+ compliance.

CPC said the mooring closures followed an inspection by Russia's transport watchdog, allowing the company to address "violations".

CPC did not specify the exact nature of these violations nor say how long the closures were expected to last.

It said the inspection was prompted by an oil product spill following the sinking of a Russian tanker in the Kerch Strait in December.

Chevron-led Tengizchevroil CVX.N, which operates Kazakhstan's giant Tengiz oilfield, did not reply to a request for immediate comment.

Kazakhstan's energy ministry also did not reply to a request for immediate comment.

Citing technical outages, Russia has closed the CPC moorings in the past. Operations were suspended in 2022 and 2023 due to damage and storms, interrupting CPC exports and hitting Kazakhstan's output.

In February, a Ukrainian drone attack struck a pumping station along the pipeline serving the terminal, according to CPC and Russian pipeline monopoly Transneft TRNF_p.MM.

The pipeline had been set to export 1.7 million barrels per day (bpd), or approximately 6.5 million metric tons, in April, Reuters reported.

It exported more than 63 million metric tons (1.4 million bpd) in 2024.

CPC's top shareholders are Transneft (24%) and Kazakhstan's KazMunayGas KMGZ.KZ (19%) while U.S. majors Chevron and Exxon Mobil also hold stakes.

(Reporting by Reuters; editing by Jason Neely)