Lack of clear policy can be messy.

• Position: Workplace Dating

The number of singles in the workplace has grown by nearly 20% since 1995, a trend that is changing the long-held rules governing dating among co-workers. As more employees relax their policies, however, some are finding that interoffice romance can have its pitfalls.

A new analysis of unpublished government data by the global outplacement firm Challenger, Gray & Christmas, Inc., Chicago, finds that the number of employed Americans who count themselves as single has grown 18.3%, from 49,835,000 in 1995 to 58,948,000 in 2005. Singles now represent 44% of the 147,100,000 people in the civilian labor force, up from 41% 10 years ago, according to data from the Bureau of Labor Statistics. Among the single workers in the labor force, 48%, or about 28,400,000 people, are in the prime dating years of 20 to 34.

"It is no wonder that workplace dating is taking off, with more than 28,000,000 young people, some of whom spend more time together in the office than they do outside of work," says John A. Challenger, chief executive officer of Challenger, Gray & Christmas. "Employers almost have no choice but to permit interoffice dating."

As many as 20,000,000 workplace romances are taking place right now, maintain some estimates. A 2003 survey by the American Management Association found that 30% of managers polled have dated an office colleague. Nearly every manager said that it is acceptable to date a co-worker, as long as he or she is not a superior or a subordinate.

"Clearly, office dating has gained acceptance over the last decade or two, but companies should be careful when it comes to workplace relationships," Challenger cautions. "Companies should attempt to establish some guidelines to avoid potential problems, including harassment claims, decreased morale, and office gossip."

Most companies do not have policies on office romance. The AMA survey found that only 12% maintain a written policy on employee dating. Among those, 92% forbid employees from dating a subordinate, while 69% disallow workers from dating a supervisor. Eleven percent ban employees from being involved with any co-worker.

"Companies that choose not to address the workplace romance issue at all could find themselves in a real quagmire if an office relationship turns sour. These situations can lead to a sexual harassment suit fairly quickly. Other problems may result if one of the individuals in a relationship is promoted. Companies may find it difficult to insist that a...