Investors are waiting for the results of the two-day Fed meeting, with speculation rife that the central bank will announce a cut in its US$85 billion-a-month bond-purchasing scheme.
In Thailand, foreign net-sell reached Bt3.48 billion on Friday. This brought net-sell this month to Bt32.6 billion and net-sell so far this year to Bt185.95 billion.
The SET index lost another 15.08 points or 1.11 per cent today, ending the week at 1,341.13 points, on turnover of Bt30.2 billion.
Global equities have seen a broad sell-off over the past four days after positive economic numbers - including falling unemployment and strong economic growth figures - have strengthened the argument for a December cut to the Fed's programme.
According to Agence France-Presse, Tokyo jumped 0.40 per cent as the yen tumbled, with the Nikkei adding 61.29 points to 15,403.1, while Sydney rose 0.71 per cent, or 35.9 points, to end at 5,098.4. But Seoul eased 0.26 per cent, or 5.02 points, to close at 1,962.91.