John Puerner, the publisher of the Los Angeles Times since Tribune Co. bought the paper in 2000, is leaving the post June 1, Tribune announced Tuesday.

Puerner, 53, said in a press release that he decided to take a “self-imposed career break” after five years of running California’s largest newspaper. Tribune spokesman Gary Weitman declined to elaborate on the reasons for Puerner’s departure, which comes on the heels of a 6.3 percent decline in daily circulation from the prior year.

Puerner will be replaced by Jeffrey M. Johnson, a longtime Tribune Co. executive who was promoted to second-in-command at the Los Angeles Times last month. Johnson, 45, joined the Times in May 2000, a month after Tribune installed Puerner as publisher, and now serves as executive vice president and general manager of the newspaper.

In the Tribune Co. press release, Johnson said he plans to “pursue strategies to expand readership and grow revenue.” He did not elaborate.