By Stephen Nellis

April 23 (Reuters) - The U.S. Department of Commerce is reviewing the security implications of China's work in open-source RISC-V chip technology, according to a letter sent to U.S. lawmakers.

RISC-V, pronounced "risk five," competes with proprietary technology from British semiconductor and software design company Arm Holdings O9Ty.F. It can be used as a key part of anything from a smartphone chip to advanced processors for artificial intelligence.

The technology is being used by major Chinese tech firms such as Alibaba Group Holding 9988.HK and has become a front in the strategic competition over advanced chip technology between the U.S. and China.

In November, 18 U.S. lawmakers from both houses of Congress pressed the Biden administration for its plans to prevent China "from achieving dominance in ... RISC-V technology and leveraging that dominance at the expense of U.S. and economic security."

In a letter last week to the lawmakers that was seen by Reuters on Tuesday, the Commerce Department said it is "working to review potential risks and assess whether there are appropriate actions under Commerce authorities that could effectively address any potential concerns."

But the Commerce Department also that it would to tread carefully to avoid harming U.S. companies that are part of international groups working on RISC-V technology. Previous controls on transferring 5G technology to China created roadblocks for U.S. firms working in international standards bodies where China was also a participant, risking U.S. leadership in the field.

(Reporting by Stephen Nellis in San Francisco; Editing by Cynthia Osterman)

((Stephen.Nellis@thomsonreuters.com;))