WASHINGTON, March 25 (Reuters) - The United States and Britain imposed sanctions on conglomerates controlled by Myanmar's military on Thursday (Mar 25), following the generals' Feb 1 coup and deadly crackdown, with Washington calling it a response to "abhorrent violence and abuses".

The US Treasury Department said its sanctions targeted Myanma Economic Holdings Public Company Ltd (MEHL) and Myanmar Economic Corporation Ltd (MEC).

Britain imposed similar sanctions on MEHL, citing the Myanmar military's serious human rights violations against Rohingya Muslims.

Representatives for the two entities, which control big sections of the Myanmar economy, had no immediate comment on when Reuters reported on Wednesday the sanctions were expected.

Thursday's actions were the most significant by far against the business interests of Myanmar's military, which range from beer and cigarettes to telecommunications, tires, mining and real estate.

Washington's move freezes any assets held by the entities in the United States and is the latest in a series of sanctions following the military takeover that have targeted Myanmar's central bank as well as top generals.

The designation also prohibits American companies or citizens from trading or conducting financial transactions with those listed.

Since almost all dollar payments clear through US financial institutions, the move effectively kicks blacklisted companies out of the American banking system.

In a statement, US Secretary of State Antony Blinken said the Myanmar military "have taken increasingly disturbing actions aimed at their own citizens since Feb 1."

"These actions will specifically target those who led the coup, the economic interests of the military, and the funding streams supporting the Burmese military’s brutal repression," he said. "They are not directed at the people of Burma.

"By designating these entities, the United States and the UK have shown that we will follow through on our pledges to promote accountability for the coup and the abhorrent violence and other abuses we have seen in recent weeks," Blinken said.

At a US Senate hearing on the response to the coup, Senator Ed Markey, Democratic chairman of the Asia subcommittee, said he welcomed the latest sanctions but called for more.

"More must be done to deny the army its economic lifeline and to deny it the weapons of war. The United States should play a leading role in urging our partners and allies, including members of ASEAN, to take steps to cut off funding for the military," he said, referring to the Association of Southeast Asian Nations (ASEAN).

Human rights groups welcomed the US move.

Human Rights Watch said the sanctions would create significant difficulties for the conglomerates in doing business with outside companies, but also said the United States could do more.

"This is a very important step but it is not the biggest economic sanction that could be implemented,” said the group's Asia advocacy director, John Sifton, adding that the United States should also target Myanmar’s revenues from natural gas joint ventures with international companies.

Global Witness urged the European Union to follow suit in sanctioning the military’s business interests, and said Britain should also follow the United States in imposing sanctions on MEC.