EXHIBIT 99.1
JOINT FILING AGREEMENT
Each of the undersigned hereby agrees that this Amendment No. 15 to the statement on Schedule 13D is being filed with the United States Securities and Exchange Commission on behalf of each of the undersigned pursuant to Rule 13d-1(k) under the United States Securities Exchange Act of 1934, as amended.
Dated: April 29, 2014
Glencore AG | |||
By: | /s/ Martin Haering | ||
Name: | Martin Haering | ||
Title: | Officer | ||
By: | /s/ Wendelin Mueller | ||
Name: | Wendelin Mueller | ||
Title: | Officer | ||
Glencore International AG | |||
By: | /s/ Martin Haering | ||
Name: | Martin Haering | ||
Title: | Officer | ||
By: | /s/ Wendelin Mueller | ||
Name: | Wendelin Mueller | ||
Title: | Officer | ||
Glencore Xstrata plc | |||
By: | /s/ Steven Kalmin | ||
Name: | Steven Kalmin | ||
Title: | Executive Officer |