* Manila has already halted 10 mines, 20 more at risk
* Minister says mines will be given time to fix violations
* Philippines is the world's top nickel ore supplier (Adds more quotes from minister, Marcventures, background)
By Manolo Serapio Jr
MANILA, Sept 30 (Reuters) - The Philippines said on Friday it may not halt operations at all 20 mines facing suspension for environmental violations and will give them time to address problems -- a softening of a tough stance that has seen 10 mines shut and a spike in nickel prices.
Asked if it was possible that not all 20 mines would be suspended, Environment and Natural Resources Secretary Regina Lopez told Reuters: "Yes, if they are able to fix whatever" needs to be fixed.
"Some of the violations though will take time to fix. So they need to use their employees to fix it. They should put measures to make sure it doesn't happen again. The welfare of the people is paramount," said Lopez, a committed environmentalist.
The Philippines, the world's top supplier of nickel ore, on Tuesday ordered the suspension of another 20 mines, sending nickel to a seven-week high of $10,900 a tonne on the London Metal Exchange. The price has since retreated, pulling back further to $10,375 on Friday after Lopez's comments.
Lopez on Tuesday said that the 20 mines, 12 of them nickel producers, will be given seven days to explain any violations and submit measures to rectify them.
Only 11 out of the Philippines' 41 mines passed a two-month audit aimed at punishing those causing environmental harm.
The 10 suspended nickel mines and those at risk of being halted account for nearly 60 percent of the Philippines' nickel ore output.
Lopez said some of the violations uncovered in the audit were minimal, while some involve the destruction of the environment and would take time to be addressed. Those with serious environmental lapses will still be suspended, she said.
The Philippine accounts for nearly a quarter of the world's mined nickel supply, most of which is shipped to China.
Marcventures Mining and Development Corp, whose nickel mine was among the 20 facing suspension, said its audit findings "are defensible and can be reversed".
In a stock exchange filing, Marcventures said there appears to have been some "unintended oversight in the audit" citing matters that have yet to be acted upon by the environment agency, including approval of its mine rehabilitation plan.
Lopez's stance on mining is backed by President Rodrigo Duterte who had warned miners to strictly follow tighter environmental rules or be shut down, saying the nation could survive without a mining industry.
Past environmental disasters, including a 1996 tailings leak at a copper mine in central Marinduque province that contaminated rivers, have spurred mining opponents in the Philippines led by the influential Catholic Church.
Miners, however, have questioned the latest review, particularly the inclusion of anti-mining activists in the audit teams.
Reporting by Manolo Serapio Jr.; Editing by Christian Schmollinger and Michael Perry