Singapore shares closed marginally lower on Monday, despite regional gains as broader markets responded well to a potential conclusion to the US shutdown.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 4,457.14 and 4,490.55 throughout the day. It ended the session at 4,488.13, down 4.11 points or 0.1% compared to Friday's close.

In company news, shares of Mm2 Asia (SGX:1B0) plunged over 25% at the close as its subsidiaries, mm2 Entertainment, UnUsUal Management, mm Plus and mm Connect received letters of demand from United Overseas Bank in relation to owed debts.

iX Biopharma (SGX:42C) was up over 9% as it entered into a term sheet with Orion Specialty Labs to establish a joint venture to manufacture and commercialize pharmaceutical and supplement products in the US.

Meanwhile, MTQ Corp. (SGX:M05) booked an attributable loss to owners of SG$2.9 million in the fiscal half year ended Sept. 30 from an attributable profit of SG$1.5 million a year earlier.