TOKYO (Reuters) – U.S. private equity firm KKR & Co Inc plans to take Japanese chip equipment maker Kokusai Electric Corp public in an IPO as early as June, three sources said, in what is likely to be Tokyo’s biggest listing in more than three years.

While the size of the initial public offering (IPO) was not immediately clear, one of the sources said Kokusai Electric would likely list with a market value of around 700 billion yen ($5.67 billion).

That would make it the biggest company to list in Tokyo since SoftBank Group Corp listed its telecom unit with a market value of 7.2 trillion yen in late 2018, according to Refinitiv data.

The Tokyo bourse is set to approve the listing as early as May, according to the three sources, all of whom declined to be identified because the matter was still private.

Lead underwriters include SMBC Nikko Securities, a unit of Sumitomo Mitsui Financial Group, and Goldman Sachs Group Inc, two of the sources said.

KKR plans to sell part of its stake to domestic and overseas investors, according to the three sources.

KKR, Kokusai Electric, the Tokyo Stock Exchange, SMBC Nikko and Goldman Sachs all declined to comment.

Kokusai Electric was spun off from Hitachi Kokusai Electric Inc in June 2018.

(Reporting by Miho Uranaka; Editing by David Dolan and Nobuhiro Kubo)