Michael Taussig QC, Debra Cherrie and Fildes will lead the new firm which will be comprised of three partners, three consultants and 10 associates.

"The days of having private client practices in a large commercial firm were probably [coming to an end] and I took the view that, consistent with a lot of family law practices, it's better to be boutique," Fildes explained. "So I thought it would be a good idea for our respective groups to join forces...It was all done with Middletons' blessing and hopefully they'll refer their family law work [to us]."

Taussig said the new firm, which is based in Melbourne, will specialise in property settlements and disputes, all aspects of de facto relationships, restructuring and estate planning, divorce and issues related to parenting.

Middletons' national managing partner Nick Nichola said the firm is looking forward to continuing a close professional association with Fildes and his new firm, as Middletons begins a new era with a purely commercial focus.

"Paul is an exceptional family lawyer and highly respected. He and his team have the full support of Middletons and we thank them for their fantastic service to the firm over many years," Nichola said.