Sir Nigel retired from DLA Piper as a partner at the end of June 2016 after nearly 40 years at the firm. He is credited with spearheading the rapid globalisation of the firm into one of the world's largest global legal businesses.
He received a knighthood in 2009 for services to the legal industry and is one of only a few people to receive this honour.
Sir Nigel Knowles said: "DWF's approach is exciting and fresh, their focus has been and continues to be centred on their clients – and anyone who knows me understands that for me, it's all about the clients.
"Andrew and his team have built something really different here. I've watched their significant progress in recent years and when Andrew talked to me about the opportunity and where he, the Board and the partners wish to take the firm, it was a very easy decision. I'm looking forward to working with Andrew and his team."
Andrew Leaitherland, Managing Partner and CEO of DWF, said: "Alan has been a fantastic Chairman over the past 10 years, helping DWF transform from a North West law firm to global legal business and we thank him for his commitment and hard work.
"Over the past few years, we have laid the foundations to create something completely different in the legal market for our clients and Sir Nigel Knowles is the perfect Chairman to help us take this forward as we develop our business – Sir Nigel is a very natural fit for DWF. We're redefining legal services, by connecting legal expertise with a broad range of products and services to solve our clients' business problems from start to finish. To have Sir Nigel join us is a huge vote of confidence in our strategy.
"His vision and talent for creating what has become one of the world's most successful law firms will be of enormous benefit to our clients and people as we focus on the next stage of our journey."
Alan Benzie commented: " After an enjoyable 10 years as Chairman of this fast growing, successful law firm , it is time to hand over the reins. Who better than Sir Nigel? His credentials and achievements speak for themselves and I am pleased that he has accepted the position. I look forward to working with him and will continue to enjoy and applaud his and this dynamic firm's continued success."