(Bloomberg) -- Several of Glencore Plc’s largest shareholders believe that the company should retain its coal assets, according to people familiar with the matter, throwing a proposed spinoff into doubt.Most Read from BloombergTesla Soars on Tentative China Approval for Driving SystemStocks Trade for 390 Minutes a Day. Increasingly, Only 10 MatterYen Sparks Intervention Suspicion After U-Turn From 1990 LowsWhat 60,000 Headlines Say About the Fed’s Next MoveElliott Built ‘Large’ Stake in Buffett-