American football and baseball apparel and equipment company Riddell Sports Group Inc was on Monday acquired by private equity firm Fenway Partners Inc for more than $100 million.

Riddell is the US' largest football helmet maker and also produces shoulder pads, related protective wear, apparel and accessories.

It posted sales of $100m last year and has licensing agreements with third parties to make and sell products under the Riddell and MacGregor brand names.

"Riddell is a company with multiple strengths, including brand recognition, market leadership, a direct sales force with longstanding institutional relationships, product innovation, and earnings stability which provide an outstanding foundation to grow the business," said Fenway chairman and CEO, Peter Lamm, in a news release.

"The management team, led by Bill Sherman, has been instrumental in guiding Riddell's success and we look forward to supporting their ongoing efforts to broaden the company's markets, expand to new sports categories, and pursue selective acquisitions."