PMK/HBH chief exec Simon Halls is ankling the Hollywood praisery as fallout continues from the PR shop’s merger with BNC. Though no official announcement’s been made, Halls disclosed his decision Wednesday at a staff meeting. PMK/HBH execs Melissa Kates and Jennifer Allen also announced plans to depart and form their own operation.The two companies currently have a combined headcount of about 160 employees. PMK/HBH prexy Nate Schreiber departed last week, and managing partners Robin Baum and Stephen Huvane ankled Monday along with execs Andy Gelb and Shawn Purdy to join up with PR vet Ina Treciokas.

Employees at the companies — both owned by advertising/marketing giant InterPublic Group of Companies — received word Monday that a merger would be completed by the end of this year. Halls hasn’t disclosed his plans and is expected to continue working at the shop during the transition.

Halls, who wasn’t available for comment, formed HBH with Baum and Huvane in 1995, and the shop merged with PMK in 2001. He became CEO in early 2008, after Pat Kingsley departed from that post.

Halls’ clients include Ang Lee, Sam Mendes, Ridley Scott, Jude Law, Ryan Murphy and Working Title.