Britain on Thursday announced sanctions against the Myanmar Economic Corporation (MEC) for its role "in serious human rights violations", a week after Washington cracked down on the military-linked conglomerate.
MEC and another military-linked conglomerate called Myanmar Economic Holdings Ltd (MEHL) dominate many sectors of the resource-rich Southeast Asian country's economy, including trading, alcohol, cigarettes and consumer goods.
After seizing power in February from a civilian government, Myanmar's military has regained control of state companies.
"Two months on from the start of the February coup, the Myanmar military has sunk to a new low with the wanton killing of innocent people, including children," Foreign Secretary Dominic Raab said in a statement.
"The UK's latest actions target one of the military's key funding streams and impose a further cost on them for their violations of human rights," he added.
Along with the US, Britain last week announced an assets freeze and travel ban affecting MEHL. Washington also took action against MEC.
Britain followed suit on Thursday, saying the sanctions against MEC will be "enforced immediately for its involvement in serious human rights violations by making funds available to the military, as well as its association with senior military figures".
The designation was in response "to credible evidence that it has contributed funds to support the Myanmar military", the Foreign Office said.
Through the two highly secretive conglomerates, at least 133 companies in the country are wholly or partially overseen by generals, according to the campaign group Justice For Myanmar.
Much of the lucrative -- and largely unregulated -- trade in jade and rubies is controlled by military-owned businesses.
MEHL has partnerships with companies in China, Japan, South Korea and Singapore, among others.
Between 1990 and 2011, some $18 billion was paid out to current or retired military officials who hold stakes in MEHL, according to an Amnesty International report in September.