Industrial Opportunity Partners (IOP) raised its third fund, Industrial Opportunity Partners III LP, at $450 million. The private equity firm raised the fund in about three months. IOP recently sold auto filter maker Kuss Filtration.

IOP is an Evanston, Illinois-based middle market PE firm that invests up to $50 million in businesses that have between $30 million and $350 million in revenue. The firm focuses on the construction, automotive and industrial sectors. Earlier in 2017, IOP-backed Monroe Truck Equipment Inc. acquired Towmaster Inc.

Private equity is experiencing the best fundraising climate in years – perhaps ever. PE firms with proven track records are faring especially well, raising funds in record time. In the first half of the year, 224 North America-focused funds closed, raising $133 billion, while globally there have been 412 private equity funds closed, which raised a combined $221.4 billion, surpassing the record $220.8 billion raised in 2008, according to Preqin.

Other middle-market fund raises include: Platte River Equity’s closing the firm’s fourth fundraise; Private Advisors’ closing its fourth co-investment program; CVC Capital Partners’ $18 billion fund to target U.S. and European investments; the Riverside Co.’s first minority investment fund in April 2017.

Park Hill Group served as IOP’s placement agenet, which received legal advice from Sidley Austin.