Despite The Straits Times Index crossing the 4,000 mark for the first time, Singapore shares slipped into the negative territory for the first time this week, in line with losses across Asia as concerns over US tariffs linger.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 3,969.01 and 4,005.18 throughout the day. It ended the session at 3,972.43, down 9.14 points or 0.23% compared to Thursday's close.

In economic news, Singapore's Import Price Index fell 3.3% year on year in February, extending the 2.2% decrease in the preceding month, according to a report by the Department of Statistics.

Singapore's Manufactured Products Price Index fell 0.5% in February, reversing a 3.6% gain in January, the Department of Statistics reported. Singapore's Domestic Supply Price Index also fell 0.7% in February after a 3.6% rise in January

Meanwhile, total loans and advances to residents in Singapore totaled SG$841.1 billion in February, with building and construction loans contributing SG$177.8 billion, according to data released by the Monetary Authority of Singapore.

In company news, shares of Singapore Post (SGX:S08) were up over 5% after the company completed the divestment of its Australian logistics business, Freight Management to Pacific Equity Partners, for AU$1.02 billion.

Wilmar International's (SGX:F34) shares were up nearly 1% after the company's near and long term emissions reduction targets were validated by the Science Based Targets initiative.

Meanwhile, shares of Singapore Telecommunications (SGX:Z74) were up nearly 1% at the close after its technology services arm, NCS, entered into a joint venture with Philippine-based Globe Telecom (PSE:GLO).