Singapore shares closed marginally in the negative territory on Wednesday, tracking broader regional losses, as investors awaited the outcome of the US Federal Reserve's policy announcement later in the day.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 4,492.46 and 4,520.96 throughout the day. It ended the session at 4,511.90, down 1.34 points or 0.03% compared to Tuesday's close.

In corporate news, shares of The Trendlines (SGX:42T) were down over 5% at the close with the company expecting to raise around SG$3.4 million through the issuance of up to 51.4 million shares at SG$0.0666 per share to 11 subscribers.

Olam Group's (SGX:VC2) shares were down nearly 1%, as its subsidiary, olam food ingredients or ofi, secured a multi-tranche dual-currency term loan facility of around $1.12 billion.

Meanwhile, Leong Guan (SGX:LGH) will make its debut on the Singapore Exchange's Catalist board on Dec. 11.