Glencore said today it would cooperate with US authorities after they demanded documents about the mining firm's business in Democratic Republic of Congo, Venezuela and Nigeria as part of a corruption investigation. 

The company said it had set up a committee of board members, including Chairman Tony Hayward, to oversee its response to the subpoena from the Department of Justice. 

"The company will cooperate with the DoJ, while continuing to focus on our business and seeking to maximise the value we create for our diverse stakeholders in a responsible and transparent manner," Hayward said. 

"Glencore takes ethics and compliance seriously throughout the group," the chairman said. 

Switzerland-based Glencore received a subpoena from the US Department of Justice last week requesting documents and records on compliance with the US Foreign Corrupt Practices Act and money-laundering statutes. 

The US Foreign Corrupt Practices Act makes it a crime for companies to bribe overseas officials to win business. 

Glencore shares have 20% since the start of 2018 and are close to one-year lows. 

The stock suffered its biggest one-day fall in more than two years after the subpoena announcement last week. 

Responding to the share fall, Glencore announced a buy back worth $1 billion in an effort to soothe investors. 

Some analysts say the US subpoena could be a result of Glencore settling a mining row in Congo with Israeli billionaire Dan Gertler, under US sanctions since last year, by agreeing to pay royalties in euros. 

Congo accounts for about 25% of Glencore's net present value, analysts said, adding that Venezuela and Nigeria's contribution was negligible. 

The firm mines cobalt in Congo, a key metal used to make batteries for electric vehicles.

One of Glencore's cobalt mines in Congo

Some analysts say the US subpoena could be a result of Glencore settling a mining row in Congo with Israeli billionaire Dan Gertler, under US sanctions since last year, by agreeing to pay royalties in euros. 

Congo accounts for about 25% of Glencore's net present value, analysts said, adding that Venezuela and Nigeria's contribution was negligible. 

The firm mines cobalt in Congo, a key metal used to make batteries for electric vehicles.