Foresight Energy Partners LP, the coal producer run by billionaire Christopher Cline, filed to raise $300 million in a U.S. initial public offering, triple the amount first sought.

The company, which disclosed the new amount in a regulatory filing today, had earlier filed to raise $100 million. The amounts are placeholders used to calculate fees and may change.

Foresight operates the most productive underground coal mine in the U.S. and generated more than $500 million in sales last year, according to the filing. Cline, who also serves as principal strategy officer, previously developed coal deposits in the Illinois basin and the Appalachian region.

Coal production rose 44 percent last year to 10.4 million tons, Foresight said. The company operates underground longwall mines in central and southern Illinois and has about 3 billion tons of coal reserves.

The miner, which is applying to list on the New York Stock Exchange under the ticker FELP, plans to use the IPO proceeds to make a distribution to Foresight Reserves. Foresight didn’t disclose how many shares will be offered or prospective prices in the IPO, which Citigroup Inc. and Morgan Stanley are leading.