Having transformed Glencore from a poorly understood commodities trader based in Baar into one of the world's largest resources companies through the spectacular $US60 billion float four years ago and the takeover of mining group Xstrata in 2013, the hard-nosed South African was lauded as a savvy deal maker.
In the context of the input sentence, determine the relationship between 'Xstrata' and 'Glencore'.
Options: owner of, owned by, stock exchange, operator