What is the relationship between Permira and Private equity in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

-- Private equity firm Permira and Ontario Teachers Pension Plan Board to jointly acquire the GFKL Group and the Lowell Group (notified Sept. 4/deadline Oct. 9/simplified)

Answer: industry