Japan\'s two biggest bourses said Thursday they have won regulatory approval for a planned merger in January amid stiff competition from overseas rivals. Following a decision by the Fair Trade Commission, the Tokyo Stock Exchange (TSE) said it would soon launch its planned takeover bid for the smaller Osaka Securities Exchange (OSE). The two bourses were aiming to merge their operations early next year with the deal expected to be completed in August, according to Japanese media. Japan has several other smaller regional bourses, including exchanges in the cities of Sapporo and Nagoya. The merger of Japan\'s two biggest securities markets comes amid an increasingly competitive landscape with slowing growth and a strong yen further eroding the benchmark Nikkei index, which peaked in December 1989 near the 39,000 level. On Wednesday, the index closed at 9,104.17, less than a quarter of its 1989 value. The bourses hope that combining the TSE, the centre of share trading in Japan with leading names including Toyota and Sony, and the derivatives-trading focused OSE will save costs and boost Japan\'s securities market. The TSE alone was the world\'s third-largest bourse behind market leader NYSE Euronext and Nasdaq OMX Group in terms of market capitalisation as of the end of 2011, according to the World Federation of Exchanges. The merged entity, tentatively called \"Japan Exchange Group\", would bring the Japanese market closer to the second-ranked Nasdaq.