This and several other findings are among the results of an internet-based survey of almost 500 companies and organizations. The survey was conducted by the U.S.-based WorldatWork, a networking membership group for professionals, and Corporate Voices for Working Families, which describes itself as a private-sector voice in public-policy issues relating to families.

The responses take on increasing weight as the work force ages.

Despite what has been cited in some quarters as a growing awareness of the greying worker, almost one-third of the survey respondents said the aging work force is of little or no significance.

Yet more than half of those surveyed identified the exodus of older workers and the corresponding departure of senior leadership as a risk they must face.

This emphasis on experience is reflected in the observation by almost 90 per cent of those surveyed that the retention of an older work force to preserve knowledge is a "very significant" business advantage.

Cost increases resulting from the loss of senior workers were listed as highly significant by almost two-thirds of the survey group.

More than 80 per cent said they have not polled their older employees to determine work plans or preferences.

Almost half of the respondents reported that the most significant strategy for keeping senior staffers was to implement flexible work schedules.