Singapore Strait Times Index slipped into the negative territory on Monday's closed despite starting the week marginally higher at the opening bell, after global equities ended the previous week mixed.

During the day, the benchmark index ranged between 3,133.72 and 3,148.82, ending 0.28% or 8.67 points lower at 3,138.42.

In company news, shares of SIIC Environment (SGX:BHK, HKG:0807) were up 1% on Monday's close, after its subsidiaries increased their equity interest in two subsidiaries.

Shares of Oversea-Chinese Banking Corp. or OCBC (SGX:O39) were largely unmoved at the close, as the company revealed that it had dissolved its wholly owned subsidiary, Horizon Asset Management.

Meanwhile, SinoCloud Group (SGX:5EK) entered a non-binding memorandum of understanding with Mark Luk Siu Fung to acquire 60% equity in two investment holding companies.