COMEX copper rallies to record high on weak dollar

Dec 28 （Reuters） - U.S. COMEX copper futures rallied by more than half a percent to a record high early on Tuesday, bolstered by a 0.5 percent drop in the dollar and support from threats to supply.

The benchmark fourth month HGc4 rallied 0.6 percent to an all-time high of 430.75 cents/lb, while the dollar fell 0.42 points to 79.946 versus a basket of currencies .

Shanghai copper SCFc3 rose also 0.6 percent to 69,140 yuan a tonne. The continued closure of Chile's Patache port terminal since a Dec. 18 shiploader accident will continue to underpin sentiment, with the Collahuasi mine maintaining production but as yet unable to secure an alternative route to get the concentrate to customers. （Reporting by Nick Trevethan; Editing by Himani Sarkar）