PARIS: Real women wear hard hats at sprawling global engineering and construction company CH2M Hill.

They serve on the board of directors and manage construction projects for the 2012 London Olympics, the Panama Canal expansion and Abu Dhabi.

Yet, it took these executives some time to crack the unwritten rules and rituals of their own company.

Beyond the thunder of pneumatic drills and backhoes, the employees of CH2M Hill - a company based in Denver, Colorado with 23,500 employees worldwide - live by the homespun codes of their company manual, The Yellow Book.

But they have also been guided by informal rules and corporate rituals, which men and women have interpreted very differently.

Female engineers hung back, failing to push for promotions and mentors, while male colleagues aggressively worked the system.

Women sought more experience to advance, while men with less training demanded more responsibility.

How to translate the code?

'There are definitely unwritten rules for how you do business and how you succeed,' said Ms Jacque Rast, a civil engineer who is president of the company's major programmes and a member of its board.

The gap between the company manual and informal rules remains wide for women in many countries.

In a newly released survey, female executives from more then a dozen European countries contended that a critical unwritten rule for corporate success is still basic: work long hours and keep a physical presence in the office.

The report came out this month from Catalyst, a non-profit group based in New York and Switzerland with a membership of more than 400 companies, which seeks to expand opportunities for women in the workplace.

As part of a series of surveys dating from 2008 on unwritten rules, the group questioned 201 women and men in Europe and found distinct differences between how male and female executives manoeuvred to advance.

Despite of a lot of high-minded corporate talk about balancing work and life, the women were more likely than men to rate visibility as important for advancement, according to the report.

They sought to rise with an old-fashioned strategy: working long hours, spending time physically in the office and publicly declaring availability to work even more hours.

'Presentism is alive and well,' said Ms Eleanor Tabi Haller-Jorden, general manager of Catalyst in Switzerland, who said company executives often bring up the issue.

'That's a fancy word for face time, which is very old school.'

She said a senior-level female executive tested this attitude after noticing jackets draped on the vacant chairs of absent colleagues.

'As an experiment, she put her jacket on a chair and started leaving at a reasonable hour,' Ms Haller-Jorden said.

'Yet, people started coming up to her and saying she was putting in a fabulous amount of hours. She said the jacket was the best investment of €250 (S$440) that she had ever made.'

The Catalyst research showed that about half of the women surveyed did not think working long hours was important, but they clearly believed it was necessary for advancement. More than 83 per cent said clocking long hours was a must.

In the highly male universe of the construction industry, CH2M Hill's top management started evaluating the firm's own culture with a keen awareness of the shifting demographics of university graduates, as growing numbers of women obtained degrees in science, engineering, architecture and construction management.

'Also, in the United States, we see more women as clients: public works, mayors, more women in government. So, the diversity of the client base has changed,' said Ms Rast.

The company's folksy manual, illustrated with cartoons, already recognised the value of flexible style and informal communication.

Written in 1982 by company founder and original chief executive Jim Howland, The Yellow Book advises employees, for instance, to 'avoid position perks such as parking spaces reserved for individuals, thick rugs, swivel thrones and oversized offices', in favour of smaller offices and efficient use of space.

Yet there were clear differences between how men and women operated within the company, when the management started to evaluate company culture.

They discovered, according to Ms Rast, that men were more reluctant to give candid feedback to women because they wanted to be polite.

Women, in turn, she said, 'generally believed their competence spoke for themselves and didn't want to appear pushy by asking for promotions, training and mentoring. So they wouldn't go and ask for one'.

With the backing of the company's top managers, CH2M Hill then sought to challenge that style with its women's network and annual meetings, which were designed to promote the idea that women had to take control of their careers by freely asking for more responsibility and training.

Critical to this effort, Ms Rast said, was the support of managers, who also instituted a policy that at least one female candidate had to be submitted in the pool of choices for management positions above a certain grade.

Since then, the company's programme for female advancement has helped to increase the number of women in top positions; they now make up almost 30 per cent of the firm and a third of the board.

For companies, according to Ms Laura Sabattini, author of the Catalyst report, such advances underline the value of checking whether corporate philosophy actually matches up with written and unwritten rules.

'Workers may be told that they can work from wherever, but when they see that those advancing are in the office a lot, then there is a disconnect,' she said.