Singapore shares closed in the red zone on Friday, tracking larger regional losses, amid uncertainty over the timeline for the next round of U.S.-Iran diplomatic talks.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 4,987.85 and 5,016.20 throughout the day. It ended the session at 4,997.93, down 9.90 points or 0.2% compared to Thursday's close.

CSE Global, YZJ Maritime up around 4%; Boustead up nearly 3%; Olam Group, iFast, First Resources, OUEREIT, AvePoint up over 1%.

Pakistan is continuing to push the peace talks, with the country's civil and military leadership visiting regional leadership to find a way forward to put an end to the Iran conflict.

In economic news, Singapore's non-oil domestic exports jumped 15.3% year over year in March, following a 4% increase in the previous month, according to data released by Enterprise Singapore on Friday.

On the corporate front, shares of Rex International (SGX:5WH) surged 28% at the close as its subsidiary, Lime Petroleum, will now look to satisfy its overdue cash call obligations through a new super senior bond issue.

Ascent Bridge (SGX:AWG) zoomed over 18% as it completed the transfer of 30% of its shares in MTBL Cultural Centre to Nyonya Heritage.

Meanwhile, MoneyMax Financial Services (SGX:5WJ) closed over 4% higher with the pawnbroker targeting to raise up to SG$44.3 million through the placement of 53 million shares at SG$0.835 each.