The ruble slumped the most among emerging-market peers as investors sold the currency of the world’s biggest energy exporter amid concern Iranian crude deliveries will extend an oil-market rout. Russia relies on the oil and natural gas industries for almost half its budget revenue and collapsing crude prices have weakened the ruble 6.6 percent versus the dollar this year, the most among developing nations after South Africa’s rand. The Russian currency retreated 1.2 percent to 78.5650 against the dollar by 11:16 a.m. in Moscow, its lowest intraday level since Dec. 16, 2014, when falling energy prices and the conflict in Ukraine drove the ruble to a record low. The lifting of international sanctions on Iran has helped raise the correlation between Brent and the ruble toward its strongest since October. Crude sank below $28 per barrel on Monday, extending declines and trading at a 12-year low. Trading will be […]