Mitsui Chemicals Agrees to Buy JSR for $11.6 Billion

Mitsui Chemicals Inc. agreed on Monday to buy chip-materials maker JSR Corp. from state-backed Japan Investment Corp. for 1.84 trillion yen, or about $11.6 billion including debt, the largest deal on record in Japan’s chemicals industry. The price is well above the roughly $8.2 billion figure that surfaced last week when Mitsui emerged as the buyer.

The Tokyo company will pay about 1.39 trillion yen for JSR’s equity, a figure that includes a 200 billion yen investment from the Development Bank of Japan, and take on about 448 billion yen of debt and other obligations. DBJ’s common shares in JSR will be converted into non-voting preferred stock after closing, leaving Mitsui with all of the voting rights. Mitsui’s shares fell about 8.5% in Tokyo trading, and its market value before the drop was roughly 665 billion yen, well under half the deal price.

A bridge, then a lot of refinancing

Mitsui lined up a 1.64 trillion yen bridge loan from its main lenders. It expects net debt to run above 4x EBITDA for a time after closing and has set a goal of protecting a credit rating in the A category. Within a year of completion it plans to replace the bridge with a mix of bank loans and bonds, up to 150 billion yen of new common shares and 300 billion yen of mezzanine financing that ratings firms would treat as half equity. It filed a shelf registration on Monday for the share sale, with SMBC Nikko Securities and Mizuho Securities expected to lead it.

JSR, which JIC took private in 2024 for about 900 billion yen, posted revenue of about 441 billion yen and core operating profit of about 62 billion yen in the year ended March 2026. Mitsui is targeting about 40 billion yen a year in added profit by fiscal 2035 by pairing JSR’s advanced photoresists with its own pellicles and back-end tapes. It also plans to sell JSR’s life-sciences arm, which includes contract manufacturer KBI Biopharma, and other assets it does not consider core.

Petrochemicals headed for the exit

The purchase reshapes Mitsui beyond chips. The company widened the planned split-off of its basic and green materials business to include its mobility solutions unit, effectively separating its commodity and auto-materials businesses from a specialty group built around semiconductors and health care. Closing is targeted for the second half of the fiscal year ending March 2028, pending antitrust and foreign-investment approvals in several countries.