* Fitch cuts US credit rating to AA+;

* Thai c.bank raises key rate by 25 bps

* China, HK stock rally fades, incremental support disappoints

* Russia June unemployment data due

* EM FX down 0.4%, stocks off 1.9%

Aug 2 (Reuters) - Emerging market stocks and currencies dropped on Wednesday, as a surprise downgrade on U.S. credit rating by ratings agency Fitch and concerns over global economic growth dealt a blow to appetite for risk assets.

The MSCI index for EM stocks lost 1.9% to a one-week low, while the currency index shed 0.4% to a three-week low.

Rattling markets globally, Fitch on Tuesday downgraded the U.S. to AA+ from AAA, citing fiscal deterioration over next three years and repeated down-the-wire debt ceiling negotiations that threaten government's ability to pay bills.

"For emerging markets the change to the U.S. credit rating does not alter the relative safe haven status of U.S. treasuries or the dollar," said Hasnain Malik, emerging and frontier markets equity strategy at Tellimer.

"The downgrade though is a reminder that the 'exorbitant privilege' of the U.S. is not limitless and there are some very strong sovereigns in EM which might deserve tighter spreads."

The dollar and yields on the two-year and benchmark 10-year Treasury notes held fort after a knee-jerk reaction.

Following a slew of weak manufacturing data on Tuesday, including China and the euro zone, analysts believe that the EM industry will continue to struggle over the rest of 2023 as global economic growth slows sharply.

China and Hong Kong stocks remained under pressure on continued profit taking in the absence of concrete and forceful measures by Beijing to shore up a flagging economy.

The yuan eased to a one-week low, down around 4% against the dollar so far this year, despite measures from regulators to curtail speculative trading.

Reuters reported China's currency regulators are asking some commercial banks to reduce or postpone their purchases of U.S. dollars in order to slow the yuan's depreciation.

South Korea's KOSPI and won also lost 1.9% and 0.6%, respectively, in line with weak global sentiment.

South Africa's rand weakened 0.6% against the dollar, after tumbling as much as 2% on Tuesday, amid persistent risk-off sentiment.

Russia's rouble steadied against the greenback ahead of three government bond auctions, supported by oil prices at a 3-1/2-month high but hampered from significant growth by geopolitical risks.

The country's June unemployment data is due during the day.

The Czech crown gained 0.3% against the euro ahead of an interest rate verdict on Thursday. Hungary and Romania are set to deliver policy decisions next week.

Egypt's rate decision is also due on Thursday.

The Thai baht reversed early losses and gained 0.2%, following a 25-basis-points rate hike to 2.25%, its seventh hike in a row. (Reporting by Ankika Biswas in Bengaluru; Editing by Rashmi Aich)