BEIJING, July 19 (Reuters) - Three-month zinc on the London Metal Exchange (LME) gave up early gains to trade sharply lower on Thursday as another broad sell-off in industrial metals took hold. Shanghai zinc had earlier jumped by the daily limit of 6 percent to a one-week top following a report that China plans to boost liquidity in the banking sector, and was underpinned by falling inventories and a weaker yuan. The LME sell-off that followed came as a China foreign ministry spokeswoman described as "shocking" comments from U.S. economic adviser Larry Kudlow that Chinese President Xi Jinping was "holding up" a deal to resolve a trade row between the two countries. Matt France, head of Asia institutional metal sales at brokerage Marex Spectron, said in a note that dips in metals prices "continue to offer up value on an intra-day basis" but "the bearish trend remains intact." FUNDAMENTALS * LME ZINC: Three-month zinc on the LME rose as much as 2.1 percent earlier in the session, but was down 3.6 percent at $2,507.50 a tonne, as of 0739 GMT. In the previous session, the metal gained 3.5 percent, its biggest daily jump in almost a year. * SHANGHAI ZINC: The most-traded September zinc contract on the ShFE touched its highest since July 10 before closing up 3.5 percent at 21,125 yuan ($3,126.99) a tonne for a second straight daily gain. * CHINA: The People's Bank of China plans to introduce incentives that will boost the liquidity of commercial banks, helping them to expand lending, according to a source with direct knowledge of the matter. * CHINA: China's zinc output fell 5 percent year-on-year to 475,000 tonnes in June, the National Bureau of Statistics said on Wednesday. * OTHER METALS: Shanghai base metals closed higher across the board, but LME copper was trading down 2.3 percent, nickel down 2.6 percent and lead down 2.5 percent in a broad sell-off. * COPPER: Three senior executives at Jiangxi Copper Co , one of China's biggest copper producers, have left their roles, the company said in a stock exchange filing on Wednesday, in a major managerial shake-up at the state-run firm.