It revealed 18-year-old Ivan Lister is set to join the team, as well as 20-year-old Jack Groundwater and 19-year-old Deenah Khan.
PM+M has also appointed part-qualified apprentice Marcus Feeney, set to join its Blackburn office.
The firm has said its new trainees will receive “hands-on” experience alongside “classroom study” as they work towards their qualifications.
Jane Parry, managing partner of PM+M, said: “Recruiting young people and maintaining our apprenticeships programme are integral elements of how we grow and develop the business.
“We are proud that many apprentices stay with us on a permanent basis and it’s always fantastic to see their careers flourish. This new intake are all talented individuals with real potential, so we are delighted they are now part of the PM+M team.”
Deenah Khan added: “PM+M is a hugely respected name in the North West, so myself and my fellow apprentices are really excited about our appointments. Our focus is now on maximising this opportunity and to give our careers a kick start.”