(Refiles to add dropped word in headline, no changes to text) (Reuters) -Italy’s Banca Mediolanum posted on Tuesday a 13% rise in its first quarter operating margin, while the net result inched lower, as the growing tensions caused by the conflict in Ukraine weigh on financial markets. The lender’s net profit fell to 114.3 million euros ($120.52 million) in the January-March period, from 133.4 million in 2021, hit by lower performance fees and other market-related effects. The Milan-based bank, which offers its products and services in Italy and abroad, said its operating margin came in at 142…