The Tokyo and Osaka bourses integrated the trading of shares Tuesday at the Tokyo Stock Exchange, making it the world's third-largest exchange by number of listed companies.

Japan Exchange Group Inc., created this year through the merger of the operating companies of the TSE and the Osaka Securities Exchange, aims to attract more foreign funds by boosting trading efficiency through the integration to meet fierce international competition.

"Now I can breathe a little easier," TSE President Akira Kiyota said at the start of trading, which went off without a hitch and saw the Nikkei 225 stock average end the morning session up 61.95 points, or 0.43 percent, at 14,568.20. The first day ended with the Nikkei at 14,599.12, a gain of 92.87 points.