At 12.30pm, the country's key index was down 5.13 points to 1,518.31, ignoring the record-breaking rally on the Dow Jones last week.
The decline also disappointed investors hoping for a continuation of the budding optimism that was seen in the FBM KLCI last week.
Meanwhile, investors will be tuned in to the special parliament sitting this week for more details on the government's national recovery plan.
"From a charting perspective, notwithstanding the tentative bouts of resilience, we reckon the key FBMKLCI remains vulnerable to more downside ahead.
"With the 25-day SMA line standing in its way, the benchmark index could pull back towards our first support threshold of 1,510 (S1)," said Kenanga Research in its weekly technical outlook.
The research house maintained its immediate resistance hurdle of 1,550 as an obstacle to further progress in the key market barometer.
Leading decliners on the blue-chip index were Petronas Chemicals falling seven sen to RM7.98, Hong Leong Bank down 20 sen to RM18.20, Hartalega shedding 14 sen to RM7.56 and MISC sliding seven sen to RM6.79.
Top actives on the broader market were SMTrack up two sen to 10 sen , MAG unchanged at 19.5 sen and Sapura Energy down 0.5 sen to 12 sen.
In Asian markets, Chinese authorities clamped down on the education and property sectors, sending equities lower while money flowed out of emerging markets into the US amid the corporate earnings season.
Japan's Nikkei was up 1.1% while South Korea's Kospi rose 0.5%.
In China, the main index slumped 2.2% and Hong Kong's Hang Seng dove 2.9%.
Australia's ASX200 was mostly flat 90 minutes from day's close.