AFGE confirmed its leader was arrested at Kiener Plaza, across from Peabody’s headquarters office, for standing in solidarity with the group and their fight over pension and benefits for union retirees of Peabody and spin-off Patriot Coal.

“I am proud to stand with these brave workers who for years put their lives on the line while Peabody padded its own bottom line,” Cox said as he was taken into custody by local law enforcement.

“The workers earned, and were promised, a fair pension and health care benefits.

“Reneging on these promises is nothing more than corporate theft, and although nobody likes getting arrested, this situation calls out for civil disobedience. Our brothers in the UMWA earned their retirement benefits, and I could not stand by while Peabody attempts to deprive them of what belongs to them.”

The rally was the UMWA’s tenth in St Louis since Patriot filed for Chapter 11 bankruptcy in July 2012.

A Peabody spokeswoman told ILN that, as it has already stated, the matter at hand was solely between the union and Patriot Coal.

“The UMWA is fully aware that Patriot was highly successful following its launch more than five years ago with significant assets, low debt levels and a market value that more than quadrupled in less than a year,” she said.

“At the time, analysts cited a bright future for the company’s based on its ‘strong balance sheet,’ ‘strong management team’ and ‘excellent valuation prospects’.”

The spokeswoman cited a recent report from Washington University professor Todd Milbourn, who noted Patriot's stock performance since the spin-off in 2007 had been "wholly inconsistent with an entity that was expected to fail”.

“In fact, its first year of performance was spectacular,” he said.

Peabody said there were a series of other “unforeseen events” that had an impacted all coal producers, and these all happened in Patriot’s time.

“These included an unprecedented global financial crisis; development of low-cost shale gas that reduced coal use; burdensome regulation by the US EPA that dramatically increased Patriot’s environmental compliance costs; an increase in safety regulations that, in turn, increased operating costs; and a significant reduction in the price of Patriot’s major product: metallurgical coal,” the spokeswoman said.

“The proper process for deciding such issues [between Patriot and the UMWA] is through the bankruptcy court.”

Peabody Energy spun off Patriot in 2007. Arch Coal spun off Magnum Coal the following year.

Patriot later acquired Magnum, and last July cited annual employee obligations as one of the sources of financial distress that led to its bankruptcy filing.