HOUSTON, May 1 : U.S. exports of liquefied natural gas to Asia jumped in April, with American producers helping offset reduced supplies from Middle Eastern exporters as the Iran war curtailed output in the region, preliminary ship-tracking data from financial firm LSEG showed. Nearly a quarter of all U.S. LNG exports went to Asia during the month, marking a sharp increase since the conflict began in late February and underscoring the growing role of the U.S. as a swing supplier amid elevated