By Rupert Hargreaves An activist investor has called for Glencore to shift its listing from London to Sydney and improve cash returns to jump-start its share price. The activist, Tribeca Investment Partners, an Australian hedge fund, has reportedly written to the company’s board with a list of proposals to boost the company’s flagging share price. The proposals included shifting the company’s primary stock market listing from London to Sydney, spinning off its coal business into a new entity, returning more cash to investors and divesting a minority stake in its lucrative trading division. The…