Century Aluminum Company - Company Announcement

Century Aluminum Delays Lockout at Hawesville, Kentucky Smelter

USW to Hold Vote on Company's Modified Last, Best and Final Offer

CHICAGO IL--(Marketwired - May 11, 2015) - Century Aluminum of Kentucky General
Partnership (the "Company"), a subsidiary of Century Aluminum Company (NASDAQ:
CENX) ("Century"), today delayed the effective time of its potential lockout of
USW Local 9423 at its Hawesville, Kentucky smelter in order to allow the union
to hold an additional vote on a modified version of the Company's last, best
and final ("LBF") offer. The vote is expected to take place on May 11. If USW
Local 9423 does not approve the LBF on May 11, the lockout is now scheduled to
commence at 8 a.m. CDT on May 12, 2015. While the Company is hopeful that the
union membership will approve the LBF, the smelter is fully prepared for the
lockout and is expected to continue to operate safely and at full production. 

The Company has created a dedicated website -- www.cakycbaupdate.com -- to keep
employees, families, community members and others apprised of the latest
developments relating to the Hawesville facility. 

About Century Aluminum
Century Aluminum Company owns primary aluminum capacity in the United States
and Iceland. Century's corporate offices are located in Chicago, IL. 

Visit www.centuryaluminum.com for more information.

Certified Advisors for the First North market of the OMX Nordic Exchange
Iceland hf. for Global Depositary Receipts in Iceland: 

Atli B. Gudmundsson, Senior Manager -- Corporate Finance, Landsbankinn hf.
Steingrimur Helgason, Director -- Corporate Finance, Landsbankinn hf.