A survey of professionals in Singapore's financial services industry shows that more than three quarters work over and above their contracted hours, global recruitment site eFinancial Careers said on Tuesday.
With many firms in the sector trying to co-ordinate with clients and offices overseas, regular early mornings and late nights are often the norm, according to the report.
It highlights a culture of long working hours in a sector which is under scrutiny following the recent death of an intern working at Bank of America Merrill Lynch in London.
(Read more: 'Grueling' hours at banks in focus after intern death )
According to the report 'The Money Never Stops,' 78 percent of workers surveyed in Singapore said they worked beyond their contracted hours, with 40 percent saying they work longer than their set hours three or more times a week, especially to participate in overseas conference calls.
"There are two key take-aways from this survey. It confirms that the financial services industry is a truly global one that requires cross-time zone communication and Singapore is increasingly at the heart of that," George McFerran, the managing director for Asia Pacific at eFinancialCareers, told CNBC.
"The other side of this is that with people working beyond their contracted hours, you start to have questions around productivity - can people really be productive in this environment?" he added. McFerran said the findings in the Singapore survey were similar to those conducted in Hong Kong and Australia, with nine out of 10 professionals polled in Hong Kong's financial services industry saying they worked beyond their contracted hours.
In Singapore, 37 percent of those polled said they had been woken up during the night by a telephone call from a colleague or clients and two thirds said they have had their annual leave interrupted by work, according to eFinancial Careers, whose clients include major banks such as HSBC, Morgan Stanley and regional heavyweight DBS.
Over three quarters of those surveyed said their weekends have also been disrupted by work.
Recruiters and human resource groups have called for changes to guidelines and working practices following the death earlier this month of Bank of America Merrill Lynch intern Moritz Erhardt.
Erhardt, who was an intern in BofA's investment banking division, collapsed at his London home after reportedly working until 6 a.m. three days in a row.
A culture of long working hours and pressure could make it difficult for the financial sector to recruit the brightest graduates, according to McFerran.
(Read more: Brussels interns protest working conditions, lack of pay )
"The current crop of graduates coming out of university today are less impressed by financial services as a career option... perhaps the best and the brightest are saying: is this what we want?," he said.
A quarter of professionals in Singapore's financial services sector work on a shift basis, the survey showed. It was conducted in July and almost 1,740 professionals took part in the poll.
- By CNBC.Com's Dhara Ranasinghe; follow her on Twitter @DharaCNBC
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