[ESPN.com] Paul Tagliabue is retiring as NFL commissioner in July after more than 16 years on the job.

The 65-year-old commissioner has led the league since 1989, when he succeeded Pete Rozelle, and had recently signed a two-year contract extension to complete the television and labor deals.

He finally got that done 12 days ago, finishing the most arduous labor negotiations since the league and union agreed on a free agency-salary cap deal in 1992.

“I believe that now is a positive time to make the transition to a new commissioner,” Tagliabue said in a statement.

Roger Goodell, the NFL’s chief operating officer, and Atlanta general manager Rich McKay are the two leading candidates to succeed Tagliabue. Baltimore Ravens president Dick Cass is considered a dark horse.