METALS-London copper sheds early gains as dollar firms, trade concerns linger

(Adds broker comment, updates prices) BEIJING, March 28 (Reuters) - London copper gave up early gains to trade lower on Wednesday, tracking a decline in equities on a firmer U.S. dollar and as global trade tensions persisted. The dollar index, which gained about 0.3 percent overnight, making metals more expensive for holders of other currencies and weighing on prices, was trading up 0.2 percent by 0722 GMT. Fears of a trade war between the United States and top metals consumer China