# Mitsui Chemicals, Sumitomo Chemical, and Idemitsu Kosan to merge polyolefin businesses

Mitsui Chemicals, Sumitomo Chemical, and Idemitsu Kosan plan to merge their polyolefin businesses by April 2026. Sumitomo will transfer its polyolefin assets to Prime Polymer and acquire a 20% stake, with Mitsui holding 52% and Idemitsu 28%.

- Type: Acquisition
- Announced: 2025-01-21
- Where: Japan
- Status: announced
- Products: polyolefins
- Sectors: [Plastics and Polymers](https://endata.com/sectors/plastics-polymers.md)

## Companies

- [Idemitsu Kosan](https://endata.com/companies/19808.md) (acquirer)
- [Mitsui Chemicals](https://endata.com/companies/19809.md) (acquirer)
- [Sumitomo Chemical](https://endata.com/companies/20503.md) (target)
- [Prime Polymer](https://endata.com/companies/31997.md) (target)

## Sources

- [cen.acs.org](https://cen.acs.org/business/mergers-&-acquisitions/Japans-petrochemical-shakegains-momentum/103/web/2025/09), 2025-01-21: "Mitsui Chemicals, Sumitomo Chemical, and Idemitsu Kosan have announced plans to merge their polyolefin businesses by April 2026."

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Data from Endata (https://endata.com/). Announcements are summarized from public sources and may be incomplete; check the linked originals.