* SSEC -1.7%, CSI300 -1.7%
* U.S., Chinese trade deputy talks to start on Thurs - USTR
* China keeps 1-year money market rate unchanged
SHANGHAI, Sept 17 (Reuters) - China stocks fell on Tuesday, after Beijing kept a key money market rate unchanged even as data pointed to downward pressure on the world's second-largest economy.
** The blue-chip CSI300 index fell 1.7% to 3,891.22, while the Shanghai Composite Index also ended down 1.7% at 2,978.12, posting its worst day since July 8.
** The People's Bank of China partially rolled over loans from its one-year liquidity facility, but kept the lending rate unchanged, a sign it is willing to maintain adequate credit to support a slowing economy but wary of excessive stimulus.
** While analysts considered it a measured move, many still expect the central bank to step up stimulus this week by guiding benchmark rates for new loans lower on Friday as central banks globally rush to loosen monetary policy.
** "The PBOC may see the liquidity released via RRR cuts as providing enough liquidity to the market," said Frances Cheung at Westpac. "A stable MLF rate does not mean LPR cannot fall. There is downside to LPR given its spread over MLF and given the lower funding costs amid the RRR cuts."
** The PBOC's move came after data the day before showed economic slowdown deepened in August, which reinforced views China is likely to cut some key interest rates this week to prevent a sharper slump in activity.
** Investors now await the latest developments in the Sino-U.S. trade talks, while doubts remain over the progress the two sides could make this time.
** Deputy-level U.S.-China trade talks are scheduled to start in Washington on Thursday, the U.S. Trade Representative's office said on Monday, paving the way for high-level talks in October aimed at resolving a bitter, 14-month trade war.
** Sectors fell across the board on Tuesday, dragged down by tech firms, with the tech-heavy start-up board ChiNextP closing 2.1% lower.
** "The approaching of the 70th anniversary (of the People's Republic of China) made investors more sensitive to changes in policies, which could cause profit-taking following strong gains in sectors like tech," said Zhou Longgang, an analyst with Huachuang Securities.
** Tech stocks had been a major driver behind a strong market rally since early August, as they are seen among biggest beneficiaries of lower funding costs amid Beijing's push for technological self sufficiency.
** The surge in oil prices, if persisted in coming weeks, could add to uncertainties in the global economy which would also put pressure on stocks, Zhou added.
** Real estate stocks were weak after data showed the country's new home prices grew at their weakest pace in nearly a year in August.
** Around the region, MSCI's Asia ex-Japan stock index was weaker by 0.82%, while Japan's Nikkei index closed up 0.06%.
** At 07:14 GMT, the yuan was quoted at 7.0912 per U.S. dollar, 0.32% weaker than the previous close of 7.0685.
** As of 07:15 GMT, China's A-shares were trading at a premium of 28.32% over the Hong Kong-listed H-shares. (Reporting by Luoyan Liu and John Ruwitch; editing by Uttaresh.V)