Singapore shares closed marginally in positive territory Tuesday, proving resilient even as regional markets retreated on news that the U.S.-Iran ceasefire is nearing collapse.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 4,915.15 and 4,953.04 throughout the day. It ended the session at 4,946.00, up 3.23 points or nearly 0.1% compared to Monday's close.

On the corporate front, OxPay Financial (SGX:TVV) surged nearly 13% at the close as it increased investment in its subsidiary, Oxygen7, through the subscription of 349,000 shares at $1 per share.

Medi Lifestyle (SGX:Z4D) plunged nearly 8% at the close as it narrowed its attributable loss to owners by 21% in the first quarter of the year to 699,000 ringgit from 881,000 ringgit a year earlier.

Meanwhile, shares of SIA Engineering (SGX:S59) were up over 3% at the close as the company's profit attributable to owners rose to SG$85.6 million in the fiscal second half ended March 31 from SG$70.8 million a year earlier.

STI up 0.1%; Seatrium up 5%; SIA Engineering up 3%; Nio up 2%; SingPost, YZJ Shipbldg up 1%.