Singapore shares closed lower on Monday, tracking broader regional losses, with the European Union countries considering hitting the US with 93 billion euros worth of tariffs.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 4,819.93 and 4,834.88 throughout the day. It ended the session at 4,834.88, down 14.22 points or 0.29% compared to Friday's close.

EU's tariff threat came after US President, Donald Trump threatened its NATO allies over their opposition of his campaign to take over Greenland.

In corporate news, shares of Secura Group (SGX:43B) were up nearly 21% at the close as its subsidiary, Soverus, secured a Singapore Government Agency contract worth around SG$21.2 million.

Charisma Energy Services (SGX:YSV) was up over 2% as its subsidiary, Jericho Solar, achieved the Ceylon Electricity Board (CEB) Sri Lanka's financial closure milestone ahead of the deadline.

Meanwhile, shares of Rex International (SGX:5WH) were down over 1% at the close as its indirect subsidiary, Lime Petroleum, was offered participating interests in a North Sea License, in the 2025 Awards in Predefined Areas (APA 2025) round in Norway.