Glencore and Rio Tinto have restarted talks over a potential megamerger to create the world’s largest mining company, nearly a year after previous deal discussions between the global miners collapsed.

Swiss resources giant Glencore said Friday it is in merger talks with British-Australian rival Rio Tinto, potentially creating the world's biggest mining group.

The mining and minerals companies cautioned that there is no certainty that any transaction or offer will be made or agreed upon.

Glencore on Thursday said that it's in "preliminary discussions" to be acquired by Rio Tinto, in what could create the world's largest mining company. Why it matters: This could have a major impact on the market for critical metals,

Rio Tinto is in early talks for a possible acquisition of Glencore , the companies said late on Thursday, in what could create the world's largest mining company with a combined market value of nearly $207 billion.