SINGAPORE (REUTERS, THE BUSINESS TIMES)- Singapore shares fell the most in more than 11 years on Monday (March 9), leading a broad tumble in South-east Asian stocks, as fears over the economic impact of the coronavirus epidemic and a crash in oil prices triggered a steep sell-off.

Oil prices plunged as much as 31.5 per cent - the most since 1991 - after Saudi Arabia started a price war following Russia's refusal to agree to a further steep cut in oil output.

Singapore's oil-related shares were hard hit, with Keppel Corp losing 9.7 per cent to close at $5.62, its lowest since November 2016.

Petrochemical firm Sembcorp Industries tumbled nearly 10 per cent to hit a more-than-15-year low.

Meanwhile, jet fuel trader China Aviation Oil dropped 9.3 per cent to $0.98. Rex International lost 28.8 per cent to 12.6 Singapore cents, with 130.6 million shares changing hands, the most on the Singapore bourse.

The three local banks also declined. DBS shares fell 8 per cent to $21.15; OCBC Bank slid 6.8 per cent to $9.52, while United Overseas Bank closed 7.3 per cent lower at $21.50.

A total of 2.19 billion shares changed hands, with a turnover of $2.64 billion, and losers outnumbered gainers by 525 to 84 as STI marked its worst session since October 2008.

Broader Asian markets fell 4.4 per cent in their worst day since August 2015 as the number of people infected with the coronavirus topped 110,000 across the world, with the outbreak reaching more countries and causing more economic damage.

"The market continues to be fear- and headline-driven, and it is difficult to imagine a durable and broad-based recovery in risk sentiments soon," Mr Vishnu Varathan, a senior economist at Mizuho Bank, said in a note to clients.

Oil- and coronavirus-driven risks are likely to deepen the sell-off in Asian markets, he added.