Sumitomo Metal Mining : Receipt of a Partial Transfer of Stock in GRANOPT

Press Release

June 28, 2017

Sumitomo Metal Mining Co., Ltd.

Receipt of a Partial Transfer of Stock in GRANOPT

Sumitomo Metal Mining Co., Ltd. (SMM) reached an agreement with Mitsubishi Gas Chemical Company, Inc. (Headquarters: Chiyoda Ward, Tokyo; President and Representative Director: Toshikiyo Kurai; Mitsubishi Gas Chemical) for its receipt of a transfer of part of the outstanding stock held by Mitsubishi Gas Chemical in GRANOPT Co., Ltd. (Headquarters: Noshiro, Akita Prefecture; President and Representative Director:Eiji Yamaguchi; GRANOPT), and concluded a memorandum on the stock transfer contract and basic joint venture contract with Mitsubishi Gas Chemical on May 31, 2017. SMM received this stock transfer on June 23, 2017. As a result, the ratios of investment in GRANOPT are now 51% for SMM and 49% for Mitsubishi Chemical Gas. GRANOPT is a joint venture with Mitsubishi Chemical Gas, and is engaged in the manufacture and sale of rare-earth iron garnet single crystals (RIG).

In SMM's business in communication devices, GRANOPT manufactures and sells RIG, while SMM Precision Co., Ltd. (Headquarters: Noshiro, Akita Prefecture; President and Representative Director: Takio Sekino) manufactures and sells communications-use optic isolators. SMM is determined to continue further reinforcing its business in communication devices.

The impact of this transfer contract on SMM's results will be minor.

Address inquiries concerning this Press Release to:

Sumitomo Metal Mining Co., Ltd.

Hideki Motoki, Public Relations & Investor Relations Department TEL: [phone]

FAX: [phone]

[Reference]

Overview of GRANOPT

1. Name: GRANOPT Co., Ltd.

2. Headquarters and plant:

   4-4 Aza-Ogibuchi, Ogida, Noshiro, Akita Prefecture, Japan

3. Capital: 150 million yen

4. Investment ratios: 51% (SMM), 49% (Mitsubishi Gas Chemical)

5. Representative: Eiji Yamaguchi (President and Representative Director)

6. Employees: 62 (as of March 31, 2017)

7. Business: manufacture and sale of RIG