(Updates prices, adds details throughout)

By Summer Zhen and Jiaxing Li

HONG KONG/SHANGHAI, Nov 6 (Reuters) - China's yuan

weakened and stock markets on the mainland and Hong Kong fell on

Wednesday, as investors leaned toward the return of Donald Trump

as president even as preliminary counting in the U.S. election

still showed a tight presidential race.

U.S. stock futures jumped and the dollar rose across

the board, as some tallies pointed to Trump making gains over

Vice President Kamala Harris in battleground states.

China's blue-chip CSI300 Index fell 0.27% after

opening a tad higher, while Hong Kong's benchmark Hang Seng

was down 2.5%.

Hong Kong-listed China tech stocks declined

broadly in early trade, dragging down the Hang Seng. E-commerce

giant JD.com ( JD ) slumped more than 5% while Meituan ( MPNGF )

and Alibaba ( BABA ) were down nearly 4%,

respectively.

The U.S. presidential election will have a meaningful impact

on China's economy and capital markets. As part of his pitch to

boost American manufacturing, Trump has promised voters he will

impose tariffs of 60% or more on goods from China.

China's equity market is in the midst of recovering from a

years-long slump as authorities promise to address weak

consumption and a downturn in the real estate sector. The CSI

300 index is up more than 20% since Sept. 23, when Beijing

started rolling out rate cuts and stimulus.

But a Trump win could stymie that rally, with technology,

defence and export sectors in the crosshairs of his policies.

Since both Democrats and Republicans are relatively united

in antagonism to China, markets may not react dramatically until

there are concrete policy changes announced.

"Although both candidates are probably hawkish toward China,

Trump is still less predictable in terms of policy, so the

prospect of a Trump win could still drag sentiment a bit," said

Kenny Ng, strategist at China Everbright Securities

International in Hong Kong.

Onshore markets were, however, holding out for more stimulus

proposals and details from the Standing Committee of China's

National People's Congress (NPC), which meets through Nov. 4-8.

"Onshore investors are more focused on the NPC meeting this

week and are waiting to see if there will be more forceful

stimulus coming through, which will have a bigger impact on the

markets compared to the election," Ng said.

The offshore yuan fell more than 0.8% versus the

dollar, its weakest since mid-August. Its onshore counterpart

was also down more than 0.55%, and China's major

state-owned banks were selling dollars to prevent the yuan from

weakening too fast, sources told Reuters.

Trump's proposed tariff and tax policies are viewed as

inflationary and therefore likely to keep U.S. interest rates

high and undermine currencies of trading partners.

During Trump's first presidency, the yuan weakened about 5%

against the dollar during the initial round of U.S. tariffs on

Chinese goods in 2018, and fell another 1.5% a year later when

trade tensions escalated.