ABN-Amro said on Friday that it has downgraded mining groups Rio Tinto and Billiton to “hold” from “buy” and cut Anglo American to “hold” from “undervalued. In a research note, analyst David Bird at the investment bank said the move reflects limited prospects for sustained further upside in the shares on a 12-month view. “This follows recent rises in mining equity prices and a less bullish view of metal prices,” the note said, though the downside was also limited — due to support from strong cash flow generation by the companies.