Lonmin, the world's fourth-largest platinum producer by market value, was at the centre of the 2012 strike which saw the "Marikana massacre", South Africa's worst police killing since the end of apartheid.

The results of the investigation headed by a retired judge and published late on Thursday blamed the mining company as well police and unions for the tragedy.

The report found that Lonmin "did not use its best endeavours" to resolve a wage dispute with workers.

Lonmin shares in London were down 3.4 percent by 0900 GMT after hitting a 3-1/2 month low earlier in the session. They were among the worst performers in the FTSE-250 midcap index <.FTMC>.

In Johannesburg, Lonmin shares were down more than 2 percent after falling to a 2-1/2 month low.

(Reporting by Silvia Antonioli; Editing by Mark Potter)