The directors of small and medium-sized companies (SMEs) are spending too much of their leisure time thinking about work, a new survey has shown.

According to O2 Ireland's annual SME lifestyle study, more than two-thirds of owner-managers in Irish SMEs contact the office by phone or e-mail when on annual leave.

Almost one-third do not take their full holiday entitlements.

According to the study, some 60 per cent of owner-managers work more than 40 hours a week, with one-third working more than 51 hours. This compares with the legal limit of 48 hours.

The study also found that 78 per cent of those questioned work at weekends. Work does not end when they leave the office either. The study found that 58 per cent of those surveyed brought work home in the evening, with almost one-quarter bringing work home every day.

It also found that 37 per cent of those questioned had missed important family events due to work commitments.

"Our survey continues to paint a picture of hard-working entrepreneurs who work longer hours than their employees, bring work home and find it hard to switch off, even on holiday," said Billy D'Arcy, head of business sales and services at O2 Ireland.

However, Dr Joan Tiernan of the school of psychology in UCD said that, while it was evident that owner-managers find it hard to switch off, in general they have a more healthy life than their employees.

"Research finds that the biggest cause of stress in the workplace is reporting to a boss," she said. "Owner-managers in SMEs, while they have other stresses, generally value the freedom which their work brings them."