Apprenticeships are being divided along gender lines, the Equal Opportunities Commission has said.
Few construction workers are female
In a report, it said Modern Apprenticeships were not opening up enough opportunities for young women and men in non-traditional job areas.
As a result they were contributing to the UK's skills shortage, the EOC said.
And careers advice for young people often involved only information that fitted traditional ideas about which jobs were "suitable" for their sex.
The report said major skills shortages in certain sectors which traditionally have employed mostly men - such as engineering, plumbing and construction - could be solved by recruiting more women.
Over the last 10 months the EOC has been examining some of the most strongly segregated sectors of the economy: construction, plumbing, engineering, information and communication technology (men) and childcare (women).
It wants the government to tackle the issue urgently, not least when it relaunches Modern Apprenticeships in the near future.
A survey of 1,000 people, carried out for the commission by BMRB International, suggested that about half - 54% of women and 47% of men - thought the advice they were given on leaving school was influenced by their sex.
The commission's chair, Julie Mellor, said: "A hundred years ago it was unusual for a woman to be a doctor or a lawyer, or for a man to be a nurse, but now it's commonplace.
"Yet our investigation shows that there are still real barriers preventing young women from choosing jobs in areas traditionally regarded as suitable only for men, like construction, plumbing and engineering.
"This is bad for individuals, who can lose out on pay and work that best suits them.
"It's also bad for employers, who lose out on talent and skills, and for the economy as a whole, which is being damaged by skills shortages."
In the survey, 67% of women aged 16 to 24 said they would have considered a wider range of career options had they been aware of differences in pay rates for jobs usually done by women and those usually done by men.
Figures for 2002-3 indicate that in engineering, 6% of those taking Foundation Modern Apprenticeships were women, and 8% of those working in engineering jobs were women.
In construction, just 1% of the foundation courses were being taken by women - who make up 1% of those working in the industry.
The EOC said the shortage of training places meant there was little incentive or need for employers to recruit trainees outside of their traditional pool.