European women's chances of progressing into senior positions in business are slimmer than in the US, according to new research.

This isn't a glass ceiling, it's just a thick layer of men

Laura Liswood Adviser to Goldman Sachs

A survey suggests women are a "virtually untapped resource" in many European firms, making it more difficult for them to compete with the US.

"The global business community has taken too long to realise the power of releasing the intellectual capital of women in leadership," said General Motors' chairman Jack Smith at a forum on the research - carried out by two American research groups.

The grim picture of sexism in Europe has come despite a recent spate of campaigns and efforts to try and ensure equality in the workplace.

Role models needed

Women have repeatedly complained about "glass ceilings" when they feel they are being prevented from advancing into management positions.

When an organisation puts women in key leadership positions they become a magnet for talented women and men

Sheila Wellington Catalyst president

Two-thirds of women surveyed said that stereotypes and preconceptions of women's roles and abilities were the leading barrier to advancement.

"This isn't a glass ceiling, it's just a thick layer of men," said Laura Liswood, an adviser to US bank Goldman Sachs.

One key problem is thought to be the lack of women bosses acting as role models.

"When an organisation puts women in key leadership positions they become a magnet for talented women and men, "said Catalyst president Sheila Wellington.

Childcare difficulties

While many firms are moving towards better working conditions for mothers, there are still serious problems in this area, the report suggests.

You can't have it all, you always have to choose

Monika Ruelh Lufthansa manage

The majority of respondents - both male and female - believed that taking advantage of parental leave or flexible work arrangements is detrimental for career prospects.

"At Lufthansa, only 50% of women managers have children," said Monika Ruelh, a general manager at the German airline.

"The childcare situation is so bad in Germany, you can't have it all, you always have to choose," she said.

The survey was carried out by the influential Conference Board research group and Catalyst, a US organisation that campaigns to advance women in business.