By Marianna Parraga

HOUSTON, Feb 26 (Reuters) - Since it first imposed sanctions on Venezuela's energy sector in 2019, the United States has granted individual licenses to some oil companies that allow them to export the South American country's oil to specific destinations.

Washington had imposed the sanctions over reports by international observers of irregularities in elections that have repeatedly kept President Nicolas Maduro in power.

U.S. President Donald Trump on Wednesday announced he was reversing a key license to U.S. producer Chevron Corp CVX.N, accusing Maduro of failing to make progress on electoral reforms and migrant returns.

In January, crude exports through active U.S. licenses averaged 450,000 barrels per day (bpd), accounting for 52% of the country's total exports, according to vessel monitoring data. But despite the authorizations, China has remained the main destination of Venezuela's oil.

The following is a list of licenses and authorizations linked to Venezuela's energy sector granted by the U.S. Treasury Department and State Department in recent years:

U.S. COMPANIES

When the U.S. imposed sanctions in 2019 through executive orders targeting the country's oil and gas sector, all U.S. imports of Venezuelan crude were immediately suspended, hitting U.S. producers with operations in Venezuela such as Chevron. U.S. service firms including SLB SLB.N, Halliburton HAL.N, Baker Hughes BKR.O and Weatherford WFRD.O were also affected.

However, the U.S. Treasury Department allowed most foreign partners of state oil company PDVSA PDVSA.UL to continue producing oil in Venezuela and exporting to destinations other than the U.S.

Under Trump's 'maximum pressure' campaign against Maduro, some firms trading and shipping Venezuela oil, including units of Russia's Rosneft ROSN.MM, also were sanctioned in 2020.

Many PDVSA partners including Chevron ceased exports of Venezuelan oil as a result, which led to a rapid accumulation of debt and dividends, and the state company began using little known intermediaries to allocate its crude to China.

In late 2022, however, President Joe Biden's administration granted an automatically renewable license to Chevron to expand operations in Venezuela and resume exports to the U.S. with the goal of recovering up to $3 billion in debt.

Trump said on Wednesday that deal was being terminated.

EUROPEAN COMPANIES

Since 2019, the U.S. State Department has issued individual authorizations to European companies including Spain's Repsol REP.MC, Italy's Eni ENI.MI and France's Maurel & Prom MAUP.PA to operate in Venezuela and export Venezuelan oil.

Most authorizations include options for the European companies to swap PDVSA's Venezuelan crude for refined products, which has eased scarcity of motor fuels and diluents for extra-heavy oil output in the OPEC country.

The permits granted during Biden's administration limited the destinations of Venezuelan crude cargoes sent by PDVSA's European partners, which has ultimately lead to an increase in imports of Venezuelan crude by authorized countries such as Spain.

INDIAN COMPANIES

Indian refiner Reliance Industries RELI.NS has also received U.S. authorizations intermittently in recent years, with the most recent in effect since 2024.

The permit has allowed small volumes of Venezuela's oil to flow to India, which was its third-largest market before sanctions were imposed.

TRINIDAD

Biden's government issued two licenses for natural gas developments between Venezuela and Trinidad and Tobago, one including Shell SHEL.L and Trinidad's National Gas Company NGCTT.UL for the Dragon offshore gas project, and another to BP BP.L for the Cocuina-Manakin project.

Both authorizations are current, with Trinidad aiming for extensions so the projects can secure first gas output to be supplied to Trinidad in coming years.

(Reporting by Marianna Parraga; Editing by Lincoln Feast.)

((marianna.parraga@thomsonreuters.com; +1 713 371 7559; Reuters Messaging: @mariannaparraga))