U.S. scrap palladium supplies tightened as junkyards, hoping to capitalize on higher prices, held onto used auto catalytic converters, fueling fears about a widening deficit as strikes in major producer South Africa dragged on, recyclers said.

Falling supplies of spent autocatalysts, by far the biggest source of palladium after mine output, come as heightened geopolitical tensions in Russia and South Africa's longest-ever strike reinforce concerns about a widening deficit