Low pay and a long work week, with shift hours to boot.

These are the main reasons why Singaporeans are leaving a rising number of job vacancies here open.

The number of vacancies here climbed 8.9 per cent to 67,400 in September, the highest in six years, according to a Manpower Ministry (MOM) report released yesterday.

Across occupations, sales assistants, security guards, waiters and office cleaners were the most sought after, accounting for 10,030 openings.

These were also the jobs which had the most vacancies that employers struggled to fill with citizens and permanent residents.

Among the top reasons cited by MOM for the high number of vacancies: unattractive pay, a long work week and physically tough work.

For shop sales assistants, there were 3,730 vacancies and their median pay was just $1,741.

For security guards, the median pay was just $1,678.

CIMB economist Song Seng Wun noted: "There's very low incentive for Singaporeans to work in those sectors because they can get better pay doing something else."

Four in five vacancies last year were in the services industry, especially in community, social and personal services. This reflected "the expansion of childcare and pre-schools, health-care and tertiary institutes", said MOM.

New shopping malls also boosted hiring in wholesale and retail trade, accommodation and food services, and administrative and support services, said the ministry in its report.

Another reason for the rise in vacancies is that companies are unable to get foreign workers to fill the gap, said Singapore Retailers Association vice-president R. Dhinakaran.

"Companies are adjusting to the quota. They're still losing workers whose contracts have expired," said Mr Dhinakaran.

The vacancy problem is exacerbated by the constant churn in the industry, with workers jumping for small increases in pay, said recruitment firm ManpowerGroup Singapore's country manager, Linda Teo.

"Employers end up poaching each other's employees in order to meet their respective manpower requirements - a vicious circle unless the supply of qualified manpower increases," she said.

The MOM report also showed that the biggest surge in vacancies was for associate professionals and technicians, including registered nurses, and enrolled or assistant nurses.

This group saw 2,450 more vacancies last year than in the year before.

But the situation should start to ease as the economy continues to cool, leading to a fall in demand for workers, said economists.

Barclays economist Leong Wai Ho said: "As the property cycle starts to weaken further and tourism grows less quickly than last year, we can expect some moderation of the tightness in the services economy."