Teaching professionals, Web developers and management executives are high on the list of positions that bosses are struggling to fill.
As a result, almost half of all job vacancies last year, 48 per cent, were for professionals, managers, executives and technicians (PMETs).
The figure has risen steadily from 2013, when it was 39 per cent, the Ministry of Manpower (MOM) said in its latest report on job openings, released yesterday.
The reason for the increase is the ongoing restructuring of the economy to focus more on higher- skilled work, said MOM.
Vacancies refer to job openings for which employers are actively recruiting workers from outside their companies.
Experts said it is a good sign that demand is strong for higher-value jobs, but they worry about mismatches in the PMET sector between employers and workers' expectations, as well as between the actual skills of workers and the skills needed. "With the Smart Nation push and tech skills being sought after, non-tech-savvy PMETs who lose their jobs may not find it easy to get a new one," said UOB economist Francis Tan.
Mr Patrick Tay, assistant secretary-general of the National Trades Union Congress and chairman of the Government Parliamentary Committee for Manpower, said the figures emphasise the need to minimise gaps in expectations of employers and workers.
"Despite a relatively low unemployment rate, tight labour market and higher job vacancies in certain sectors, we need to find new ways to overcome the LTU (long-term unemployed) challenge because that is the group which is most vulnerable and in need," he said in a Facebook post.
Most of the PMET vacancies are in sectors such as community, social and personal services; financial and insurance services; professional services; and information and communications.
PMET vacancies were filled faster than rank-and-file openings, with only about two in 10 PMET positions staying open for at least six months.
The biggest hurdles employers cited were the lack of relevant work experience and candidates finding the pay unattractive.
For example, for software, Web and multimedia developers, many candidates lacked work experience and specialised skills.
For registered nurses and enrolled or assistant nurses, employers pointed to unattractive pay and shift work as the main reasons for the unfilled vacancies.
As for non-PMET openings, more than half were not filled for at least six months, particularly for service and sales workers.
Working conditions such as longer work hours, shift work and the physically strenuous nature of the jobs continue to deter locals, the ministry said in its report.
Overall, the number of job vacancies has been shrinking in the past two years, amid a slower economy and push for higher productivity.
A total of 53,800 jobs were up for grabs as of end-September last year, down from 60,000 in the previous year and the 2014 peak of 67,400.
One employer struggling to find staff is StarVision Information Technology.
Managing director Jason Lim said the company, which provides mobile e-commerce solutions, has been hungry for app developers for several years.
"Maybe people are unsure about joining SMEs, and I think not many people are trained in software development yet," he said.
Meanwhile, PMET worker B. Chan, 26, has been looking for a corporate communications position for the past year, but most vacancies are for people with three to five years of work experience.
He has about 11/2 years of experience in public relations. "Often, they want a person who has managed a team, which is usually rare for people with less than two years of work experience."
The ministry said employers should review their requirements for work experience to widen their pool of prospective candidates.
"This will provide more opportunities for young job entrants and mid-career PMETs to build up their domain knowledge and experience on the job," it said.