Copper pushed higher for a fourth straight day on Monday after a promise from German and French leaders to resolve the European debt crisis dented the dollar's safe-haven appeal and ignited a broad-based risk rally. In New York, the key December COMEX contract surged 9.45 cents, or 2.9 percent, to settle at $3.3680 per lb, near the upper end of its $3.2775 to $3.3910 session range.