Tim McOsker, who was chief of staff to former Los Angeles Mayor James Hahn, has joined the law firm of Christensen, Miller, Fink, Jacobs, Glaser, Weil & Shapiro, LLP, the firm announced Friday.

McOsker, who plans to start work with the Century City law firm after Labor Day, will focus on project entitlements and various transactional matters. He said he made contact with the firm last month through partner Peter Weil, who was a Hahn appointee to the Airport Commission and a staunch defender of Hahn’s plan to overhaul Los Angeles International Airport.

McOsker, 42, served eight years as Hahn’s chief of staff, starting in Hahn’s last term as City Attorney. He was one of the former mayor’s most trusted aides and had a reputation for running a tight ship.

Previously, McOsker was a partner in the law firm of Burke, Williams & Sorensen, during which time he served as the contract city attorney to the cities of Downey, Manhattan Beach, Bellflower and Lomita.