Refer to the input text as context and select the correct relationship between 'Xstrata' and 'Glencore' from the available options.
Options: distributed by, platform, owned by, operator

Glencore took a $US7.7 billion write-down in 2013 on the $US29 billion "merger" with Xstrata it executed the same year, with the bulk of that taken on goodwill.
owned by