Adds more details, comments in paragraphs 5-10

By David Shepardson and Lananh Nguyen

WASHINGTON, Jan 22 (Reuters) - The Senate Commerce Committee said on Wednesday it would hold a Jan. 29 hearing on President Donald Trump's nominee to lead the Commerce Department, the agency that has become a key U.S. tool in its efforts to constrain China's tech sector.

Trump tapped Wall Street CEO Howard Lutnick to lead the department and his trade and tariff strategy. The head of brokerage firm Cantor Fitzgerald, Lutnick will also have "additional direct responsibility" for the U.S. Trade Representative's office, Trump said last year.

Lutnick also runs brokerage BGC Group BGC.O and is chairman of Newmark Group, a commercial real estate services firm, and FMX, a platform owned by some of Wall Street's biggest banks and traders.

In a document seen by Reuters, Lutnick said that if confirmed he would resign from his positions at Cantor, BGC and Newmark and divest assets including his interests in those entities.

Lutnick, who is worth $1.5 billion, according to Forbes, also filed an extensive financial disclosure form that details his holdings.

The Commerce Department oversees a sprawling array of functions with nearly 47,000 employees, from the U.S. Census Bureau to weather forecasting, ocean navigation and investment promotion.

Commerce authority over export controls on sensitive U.S. technologies have put it at the center of trade conflicts with China, as well as investigating anti-dumping and anti-subsidy cases that often result in punitive tariffs to protect domestic industries.

Fearing Beijing could weaponize American technology to strengthen its military, both the Trump and Biden administrations have used Commerce Department authorities aggressively to impose regulations to halt the flow of U.S. and foreign technology to China - with a special emphasis on semiconductors and the equipment used to make them.

Over the past two years, the U.S. has issued sweeping export controls on advanced chips and chipmaking equipment to China, which has limited its access to cutting-edge chips for artificial intelligence and equipment needed to produce the next generation of semiconductors.

In Biden's final days in office, Commerce further restricted AI chip and technology exports, finalized rules effectively bar nearly all Chinese cars and trucks from the U.S. market and said Trump should consider banning all Chinese drones. Trump this week rescinded an executive order on AI safety that Biden signed in 2023.

(Reporting by David Shepardson; Editing by Sandra Maler and Gerry Doyle)

((David.Shepardson@thomsonreuters.com; 2028988324;))