As the prospect of a tight U.S. presidential race continues to leave financial markets in a state of uncertainty, Japanese companies remain on alert for any clues that could prompt them to change their business plans.

The yen's strengthening against the dollar, in particular, is expected to become a headwind for major exporters that have reaped the benefits of a profit-boosting weak yen.

Japanese executives and analysts are trying to gauge the implications of what some U.S. media are now describing as a neck-and-neck race, for U.S. economic, trade and currency policies.