* South Africa platinum sector has been marred by labourviolence
* NUM says six members have been murdered at Northam
* Company urges workers to resume after output suspendedMonday
* Sector is struggling with depressed prices, rising costs (Adds AMCU comment, Northam urges workers to resume)
By Ed Stoddard
JOHANNESBURG, June 7 (Reuters) - Workers at NorthamPlatinum's South African mine said on Tuesday they would notreturn to work until management and police provided them withsafety guarantees after a spate of murders, despite appeals fromthe company that it was safe.
Northam suspended production at Zondereinde mine on Mondayafter a worker was fatally stabbed during a clash betweenmembers of the National Union of Mineworkers (NUM) and the rivalAssociation of Mineworkers and Construction Union (AMCU). Thecompany on Tuesday urged workers to return to the mine.
The clashes heightened concern over a potential repeat ofoutbreaks of union violence that resulted in deaths andoperational stoppages across the sector.
South Africa is the world's top producer of the preciousmetal used for catalytic converters in automobiles, but theindustry is battling with labour unrest, soaring costs anddepressed prices.
AMCU president Joseph Mathunjwa told Reuters members of hisunion will not return to work as they still felt unsafe.
Mathunjwa said Northam had sent text messages to its membersasking them to resume work but they would not heed the call.
"How are workers going to go back when they are beingattacked and stabbed?," he said.
NUM has said that one of its members was the victim of afatal shooting on Sunday and that five other workers have beenmurdered at Northam.
A spokeswoman for the company said that five employees havedied over the past year in what she described as separateisolated incidents that occurred off the mine site and werebeing investigated by the police.
The Zondereinde mine produces about 300,000 ounces ofplatinum a year, according to Northam's website, and accountsfor about 70 percent of the company's revenue.
Northam, the world's third largest platinum miner by marketvalue, reported a first-half loss in February partly due to lowplatinum prices and impairments.
NUM spokesman Livhuwani Mammburu said the union, which isthe majority union at Northam, planned to hold a mass meeting atthe mine later on Tuesday and wanted the police and managementto address the workers and assure them about the steps beingtaken to quell the violence.
A wildcat strike at Lonmin's Marikana minein 2012 erupted in similar circumstances and ended with thepolice shooting 34 miners dead.
The AMCU has unseated NUM as the main union in the platinumbelt in recent years in often-violent circumstances.
"This is not about union rivalry to us, it is about ourmembers being killed," Mammburu said of the situation atNortham.
The latest flare-up also comes ahead of what are expected tobe tough wage talks at Anglo American Platinum, ImpalaPlatinum and Lonmin. (Additional reporting by Zandi Shabalala; Editing by JamesMacharia and David Evans)
