Sound Point Capital Management LP, a hedge-fund firm run by one of Mr. Ergen's former bankers, has been buying up LightSquared debt and now holds more than $600 million of the wireless company's roughly $1.7 billion bank loan, said people familiar with the trades.
It is unclear whether Mr. Ergen or his company, satellite-television operator Dish Network Corp., DISH +0.87% has played a role in Sound Point's trading. Mr. Ergen hasn't addressed the trades, and the company declined to comment.
The position gives Sound Point, which holds roughly $1.8 billion in assets, greater influence over LightSquared's bankruptcy proceedings and the potential to try to wrest control of the case from Mr. Falcone, the company's main backer through his hedge-fund firm, Harbinger Capital Partners. The trades, some occurring as recently as last week, have piqued the interest of those involved with Mr. Falcone's efforts to rework LightSquared's finances, as they try to determine Sound Point's motives.