By Svea Herbst-Bayliss NEW YORK (Reuters) – Harvard University’s endowment fund, the world’s largest university endowment, lost money during the last year, marking a dramatic U-turn from the previous year’s double-digit gains. Rattled by tumbling global markets, Harvard Management Co said it lost 1.8% in the fiscal year ended June 30, leaving the total endowment at $50.9 billion. University officials called the return a “very good result” viewed against the backdrop of stock and bond market declines, but acknowledged the previous year’s 34% gain, which swelled the endowment to $53.2 billion, “…