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Investments | 12 Months Ended
--- | ---
Dec. 31, 2017
Rio Tinto plc [member] |
Disclosure Of Investments In Subsidiaries Joint Ventures And Associates [Abstract] |
Investments |
Strategic report |  | Governance report |  | Financial statements |  | Production, reserves and operations |  | Additional information
B Investments
| 2017 US$m | 2016 US$m
Investments in Group companies: |  |
At 1 January | 36,050 | 36,180
Additions | 45 | 58
Disposals | - | (160)
Other adjustments | (2) | (28)
At 31 December | 36,093 | 36,050
At 31 December 2017 the Company had the following principal subsidiaries:
Company | Principal activity | Country of incorporation | Percentage shareholding
Rio Tinto International Holdings Limited | Holding company | UK | 100
Rio Tinto European Holdings Limited | Holding company | UK | 100
In accordance with Section 409 of the UK Companies Act 2006, a full list of related undertakings is disclosed in the consolidated financial statements (note 46). 1

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