In Japan's biggest overhaul of its equity markets in adecade, the TSE will adopt tougher listing criteria for its top category, hoping to highlight companies with strong profitability whose governance meets global standards, with the aim of luring more foreign investors.

Of 2,185 firms now listed on the main exchange, 1,841 have chosen the prime market, but 296 firms have not met the criteria, said the TSE, which is owned by Japan Exchange Group Inc..

Companies that fall short of the new rules can still stay on the prime market in an unspecified transition period by submitting improvement plans, a provision some investors say waters down the reshuffle.

Stricter rules for liquidity - market capitalisation in tradable shares of at least 10 billion yen ($90 million) with a tradable share ratio of 35% or more - are especially tough for small cap firms or those largely owned by parent companies or business partners.

The number of firms that have failed to meet the criteria was "higher than we expected," said Keiichi Ito, SMBC Nikko Securities' chief quants analyst.

But Ito said the reform will prompt companies to unwind cross-shareholdings, the common practice in Japan where companies take stakes in partners to cement relationships.

"This is positive from corporate governance perspectives," he said.

The bourse's overhaul is part of a long policy drive begun under former Prime Minister Shinzo Abe to win foreign investors back to Tokyo's market, which Japan fears is increasingly overlooked by global institutional asset managers.

In the April 4 re-organisation, the exchange will reshuffle its four existing markets into three, designated as "prime", "standard" and "growth".

(Reporting by Makiko Yamazaki and Junko Fujita; Additional reporting by Yuki Nitta, Noriyuki Hirata, Mayu Sakoda; Editing by David Dolan and Clarence Fernandez)

By Makiko Yamazaki and Junko Fujita