College basketball's "March Madness" may cost employers as much as $1.7 billion in productivity, according to an annual survey by Chicago-based placement firm Challenger, Gray & Christmas Inc.

The figure is based on the 37.3 million workers expected to participate in office pools during the National Collegiate Athletic Association's men's basketball tournament, and the 1.5 million expected to watch games online from their desks.

The 65-team tournament, which begins March 18 in Dayton, Ohio, has become so popular even non-sports fans follow the games and participate in betting pools. While the games can boost office morale, it comes at the expense of the bottom line, said John Challenger, chief executive officer of Challenger, Gray & Christmas.

"Those who insist there will be no impact are kidding themselves," Challenger said in a statement. "The key for companies is finding a way to maximize the positive aspects of March Madness so that they outweigh the negatives."

For every 10 minutes workers spend on basketball, companies will lose about $109 million, Challenger said. That figure is based on the current average hourly wage for all American workers, which the Bureau of Labor Statistics pegs at $17.50.

In a typical office pool, participants pick the winners of all 63 games, deciding which teams will win in the first five rounds and the championship game, which is scheduled for April 7 in San Antonio.

As much as $750 million is wagered on the tournament in office pools each year, said Terry Elman, acting executive director of the Council on Compulsive Gambling of New Jersey. While laws vary from state to state, almost all office pools are illegal.