Phil Falcone, the billionaire investor whose Harbinger Capital Partners owns wireless satellite company LightSquared, said yesterday that he expended considerable energy in 2012 and 2013 trying to work out who was buying up LightSquared's debt, Reuters reported yesterday. The purchases, which later turned out to have been made by Dish Network Corp. Chairman Charles Ergen, are at the center of a trial in the U.S. bankruptcy court in New York this week. LightSquared and Falcone accuse Ergen of hiding his identity as the purchaser to overcome restrictions on competitors such as Dish from buying LightSquared debt. Ergen, who testified in the trial earlier this week, said that he bought the debt on his own behalf and not for Dish.