Also taking place this week is the US delegation's visit to Beijing for trade talks although observers have low expectations for a breakthrough.
By 12.30pm, trading volume on Bursa Malaysia was 1.4 billion shares valued at RM816.54mil. There were 472 declining stocks, 269 gainers and 378 unchanged.
Bank counters were mostly in the red, led by Public Bank down 24 sen to RM22.18, CIMB down four sen to RM5.10, Maybank down one sen to RM8.72, RHB down 14 sen to RM5.51, Hong Leong Bank unchanged and Ambank up one sen to RM4.25.
Meanwhile Genting counters also took a step back after the previous week's rally on news that its dispute with Fox had been resolved.
Genting slipped six sen to RM7 and Genting Malaysia shed three sen to RM3.87.
Among the most actively traded on Bursa Malaysia, Priceworth was unchanged at 6.5 sen, Ekovest jumped 4.5 sen to 87 sen and KNM was unchanged at 43 sen.
MSM continued its rapid ascent following an 18% jump on Friday. At midday, the counter was up a further 29 sen or 21% to RM1.67.
Over the region, key markets were in the red albeit slightly as investors awaited more clarity on the coming Fed decision.
The Shanghai Composite Index slid 0.1%, the CSI300 Index dropped 0.1% and Hong Kong's Hang Seng Index fell 1.2%.
Japan's Nikkei Index dipped 0.4% and South Korea's Kospi Index dove 1.5%.
Oil prices fell over souring sentiment over the economy while tensions in the Middle East eased after talks between Iran and the major power concluded over the weekend.
US crude slipped 10 cents to US$56.10 a barrel and Brent crude dropped 22 cents to US$63.24 a barrel.
In currencies, the ringgit was unchanged against the US dollar at 4.1200. It rose 0.1% against the pound sterling at 5.0936 and the Singapore dollar firmed 0.1% against the Singapore dollar at 3.0029.
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