Despite BHP Billiton's spin off and sale of about $15 billion of unwanted assets over the last three years, the biggest miner remains saddled with a portfolio of even harder-to-shift rejects. A total of nine assets — from a US thermal coal mine to UK oil and gas platforms — haven't made the cut for a new slimmed-down parent or the demerger company South32. The unloved operations, valued at more than $2.8 billion according to RBC Capital Markets, are hampering Chief Executive Officer Andrew Mackenzie's quest to halve the size of BHP's core portfolio to focus on big ticket earners including crude oil, iron ore and copper. "They did the big clean up with South32 and these are what are left," said Michelle Lopez, a Sydney-based investment manager at Aberdeen Asset Management Ltd., which holds BHP shares. "I'm sure they've been on the sale slate for a long time. It's a disappointment."