Johannesburg - NUM said on Friday that it was still open to wage talks with Eskom after rejecting a 5% pay rise.
The union on Wednesday seemed to suggest it expected talks to break down because South Africa's energy regulator Nersa had declined to raise tariffs by as much as cash-strapped Eskom had requested.
But on Friday, NUM said Eskom's failure to secure the tariff increase it wanted could not be used as an excuse for wage demands not being met.
"Our members demand a salary increase of 18% for the lowest paid workers and 15% for the highest paid workers," union spokesperson Livhuwani Mammburu said in a statement.
Negotiations between Eskom and the union began on Tuesday.