BUZZ — Mercury NZ trims losses after Morningstar highlights resilient Q1 performance
* Mercury NZ shares fell as much as 1.3% to NZ$6.69 before trimming losses, and were last down 0.6% in late-afternoon Wellington trade * Electricity retailer posts Q1 trading margin up 19% YoY, as new wind and geothermal supply offset weak hydro output from dry conditions * Morningstar says one of the driest quarters o