Rio Tinto Receives Shares of Mason Resources Corp.

LONDON, UNITED KINGDOM--(Marketwired - May 10, 2017) - Rio Tinto plc ("Rio Tinto") announced that, pursuant to a plan of arrangement (the "Arrangement") between Entrée Resources Ltd. (formerly Entrée Gold Inc.) ("Entrée") and Mason Resources Corp. ("Mason Resources"), Rio Tinto International Holdings Limited, a wholly owned subsidiary of Rio Tinto, received 7,455,058 common shares of Mason Resources ("Mason Shares"), representing approximately 9.58% of the number of Mason Shares outstanding after giving effect to the Arrangement.

Rio Tinto also indirectly owns approximately 50.8% of the issued and outstanding common shares of Turquoise Hill Resources Ltd. ("Turquoise Hill"), and is therefore deemed to have indirect beneficial ownership over an aggregate of 6,209,699 Mason Shares received by Turquoise Hill pursuant to the Arrangement, representing approximately an additional 7.98% of the number of Mason Shares outstanding after giving effect to the Arrangement.

The Arrangement was effected pursuant to a plan of arrangement under the Business Corporations Act (British Columbia) whereby, among other things, each existing common share of Entrée was exchanged for one new common share of Entrée and 0.45 of a Mason Share.

Prior to the completion of the Arrangement, Rio Tinto did not beneficially own any Mason Shares. As a result of the Arrangement, Rio Tinto now owns (or is deemed to beneficially own) an aggregate of 13,664,757 Mason Shares representing approximately 17.56% of the outstanding Mason Shares.

Rio Tinto acquired beneficial ownership of the Mason Shares pursuant to the Arrangement. Rio Tinto has no intention of acquiring additional securities of Mason Resources. Depending upon its evaluation of the business, prospects and financial condition of Mason Resources, the market for securities of Mason Resources, general economic and tax considerations and other factors, Rio Tinto may decrease its beneficial ownership of securities of Mason Resources through market transactions, private agreements or otherwise.

An early warning report in respect of the above transaction will be filed under the profile of Mason Resources on SEDAR at www.sedar.com and may also be obtained by contacting the person named below.

The head office of Mason Resources is located at 1201 - 1166 Alberni Street, Vancouver, BC, V6E 3Z3, Canada. The head office of Rio Tinto is located at 6 St. James's Square, London, SW1Y 4AD, United Kingdom.