SINGAPORE - Shares of embattled Noble Group jumped 6.5 per cent to 90.5 cents when trading opened on Friday, snapping four days of losses.

Noble was the most active counter on the mainboard of the Singapore Exchange, with about 27.26 million shares changing hands. Its shares up 4.7 per cent at 89 cents at about 10:10am.

This came after Noble announced on Thursday that a second institutional investor had raised its stake in the group, giving the commodities trader a much-needed vote of confidence amid fierce market scrutiny over its financials. A unit of insurance giant Prudential raised its interest in Noble from 4.94 per cent to around 5.01 per cent to become a substantial shareholder. A day earlier, investment company Invesco raised its stake in Noble from around 4.95 per cent to 5.21 per cent.

The institutional support follows allegations from Iceberg Research that Noble used fraudulent accounting to hide potential losses while exaggerating profit and asset value. The company's alleged high level of debt was also raised by the anonymous research group. Noble has rejected the claim and linked Iceberg to an employee it fired in 2013.

Its stock has been under pressure since the first Iceberg report was released on Feb 15 and is now down nearly 30 per cent, closing at 85 cents on Thursday, their lowest since September 2013.