* Gold Fields says workers did not return to KDC West
* Strike spreads to Beatrix mine
* Close to 24,000 Gold Fields workers now on strike
JOHANNESBURG, Sept 25 (Reuters) - World No. 4 bullion producer Gold Fields said workers reneged on a deal to end a two-week strike at its KDC West operation in South Africa and miners at its Beatrix mine had also downed tools.
A wave of wildcat action is roiling South Africa's mines, including a six-week stoppage at platinum producer Lonmin last month in which 45 people were killed.
"The strike is still on, they ignored the agreement reached Friday night. And the strike has now spread to Beatrix," Gold Fields spokesman Willie Jacobsz told Reuters.
Gold Fields said on Friday the National Union of Mineworkers (NUM) agreed that some 15,000 workers at KDC West would return to work Monday night.
The strikers' demands included the resignation of local NUM leaders, a reflection of discontent among miners who regard the union as being out of touch and too closely aligned to the ANC government and company managers.
Gold Fields said almost 9,000 workers from its Beatrix mine had gone on strike.
Between the two mines Gold Fields is losing about 2,300 ounces of production per day, over 20 percent of the company's global output.
Fuelled in part by glaring income disparities, illegal strikes erupted in the platinum sector in the form of a bloody turf war between the NUM and the more militant Association of Mineworkers and Construction Union (AMCU).
The strikes have now spread to the gold sector but there is no evidence yet of AMCU involvement in the unrest.
World No. 1 platinum producer Anglo American Platinum was silent on Tuesday about an illegal strike at four of its South African operations after it threatened to take unspecified legal action against employees who did not return by the late shift on Monday night.
The mines account for about 25 percent of Amplats' output of close to 2.4 million ounces a year, according to Reuters' calculations.
Workers are also on an illegal strike at a South African mine run by AngloGold Ashanti, the world's third largest bullion producer.
South Africa is home to around 80 percent of known global platinum reserves and is a major producer of gold and coal.
Employees at Coal of Africa's (CoAL) Mooiplaats colliery in South Africa downed tools on Tuesday in a legal strike over wages.
CoAL's shares fell almost 18 percent at one point after it said employees who are members of NUM had rejected the company's offer to raise pay by 22 percent.