Two of the largest Singapore-listed oil services companies reported a combined loss of S$1 billion in the fourth-quarter, in the biggest oil-related bloodletting on Singapore equities so far.

While rig builder Sembcorp Marine reported losses of S$537 million for the three months ended Dec 31, 2015, the losses at shipyard Cosco Corporation were S$484 million.

Bloomberg data going back to 1990 showed this was the worst ever earnings for both the companies.

The results indicated shareholders in offshore and marine sector companies were in for more pains as oil prices dropped from $110 a barrel in mid-2014 to $30 currently.

With ol services companies being hit by the weak commodity prices, the pain will be passed on to lenders to the industry.

United Overseas Bank (UOB) reported a narrow rise in profits on Monday, despite the slowdown.

The bank said risks are largely manageable as underlying economic fundamentals are strong after reporting a 0.3 percent rise in fourth-quarter net profit.

Bigger rivals OCBC Bank the DBS Group are scheduled to report quarterly results this week.