Singapore shares extended losses from the previous session to start week in red, as investors await the anticipated US Federal Reserve's rate cut this week.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 4,502.88 and 4,534.44 throughout the day. It ended the session at 4,507.08, down 24.28 points or 0.5% compared to Friday's close.

In economic news, Singapore's foreign exchange reserves rose to SG$518.1 billion in November from SG$510.4 billion in the preceding month, according to preliminary data from the Monetary Authority of Singapore released Monday.

In corporate news, shares of Sembcorp Industries (SGX:U96) were down nearly 2% at the close as the company confirmed reports of ongoing negotiations to acquire Australia's Alinta Energy.

Rex International's (SGX:5WH) slipped over 3%, as its subsidiary, Jasmine Energy, raised $25 million in senior secure bonds with a three-year tenure to execute a planned drilling campaign in Oman.

Meanwhile, Addvalue Technologies (SGX:A31) received new orders worth around $4.8 million for its advanced digital radio-related business.