(Updates to the close)

SHANGHAI, Aug 1 (Reuters) - Mainland China and Hong Kong

stocks extended their declines on Friday, posting their steepest

weekly losses since April, weighed down by soft domestic

economic data and worries over global trade following U.S.

President Donald Trump's new tariffs.

** At the close, the Shanghai Composite index had

fallen 0.37% to 3,559.95 points, while the blue-chip CSI300

index had lost 0.51%.

** For the week, the SSEC slipped by 0.94% and the CSI300

dropped by 1.75%. Both indexes booked their first weekly losses

in six, and were down by the most since early April when Trump

first initiated reciprocal tariffs.

** In Hong Kong, the Hang Seng index tumbled 1.07% to

24,507.81 points, while the Hang Seng China Enterprises index

fell 0.88% to 8,804.42 points.

** For the week, the benchmark HSI plummeted 3.47%,

recording the first weekly loss in a month and dropping by the

most since early April.

** Trump slapped steep tariffs on exports from dozens of

trading partners, pressing ahead with his plans to reorder the

global economy ahead of a Friday trade deal deadline.

** "The U.S. deals with other economies will also affect

China's trade outlook," economists at ANZ said in a note on

Friday.

"If the U.S. fully enforces around 20% tariffs and 40%

transshipment tariffs on ASEAN, which accounted for 17.8% of

China's exports in the first half of this year, the supply chain

activity in the region will be strained."

** Meanwhile, the United States believes it has the makings

of a trade deal with China, but it is "not 100% done," U.S.

Treasury Secretary Scott Bessent said on Thursday.

** China's factory activity contracted in July, both

official and private surveys showed, suggesting the economy lost

momentum following robust growth in the first half of the year.

** "After a more resilient than expected trade environment

in the first half of 2025, momentum could soften a bit further

in July," said Lynn Song, chief economist for Greater China at

ING, noting market attention will be shifted to trade data due

next Thursday for more clues on the health of the broad economy.

** Around the region, MSCI's Asia ex-Japan stock index

was weaker by 1.41%, while Japan's Nikkei index

closed down 0.66%.