Michael Lombardo is exiting his post as president of HBO Programming, according to industry sources, ending a 33-year run that made him a major player in the pay TV giant’s growth and evolution.

It’s understood that the decision to step down was Lombardo’s. HBO has been under unusual pressure on the programming front in recent months but sources said Lombardo was not pushed. He’s expected to work out a production pact with the network, a shift he has considered making for some time after nearly a decade at the top of HBO’s vast programming operations.

It’s not immediately clear how HBO will reorganize to fill Lombardo’s responsibilities. He oversees programming for HBO and Cinemax as well as HBO Films, HBO Sports and HBO Documentaries and Family. He also oversees HBO’s marketing, legal and business affairs departments.

During his long tenure, Lombardo spearheaded the team that raked in countless Emmys for such signature HBO series as “Game of Thrones,” “Veep,” “Silicon Valley,” “Girls,” “True Detective,” “True Blood,” “Boardwalk Empire” and “Last Week Tonight with John Oliver.” On the longform front, HBO’s major productions on his watch included “The Normal Heart,” “Behind the Candelabra,” “Too Big to Fail,” “Grey Gardens,” “Olive Kitteridge,” “Temple Grandin” and “Game Change.”

Lombardo has long been well-liked by HBO talent for his enthusiastic support of the creative process and for his taste in material. But HBO has of late faced some missteps on the programming front. The debut of high-profile drama series “Vinyl” was met with mixed reviews, resulting in a showrunner change for the upcoming second season. The second season of “True Detective” fell flat from a critical perspective, prompting Lombardo to acknowledge that he erred in pushing series creator Nic Pizzolatto to turn around the second edition on a quick timetable.

Last August, HBO abruptly halted production on its long-gestating miniseries “Lewis & Clark” and ousted director John Curran, a costly move as filming the ambitious six-hour production was well under way. Another highly anticipated drama series, “Westworld,” has had numerous production struggles and had to push back its premiere date by months. Drama series “The Leftovers” has struggled to connect with a big audience and will end after its upcoming third season.

With the final seasons of “Game of Thrones” on the horizon, the thin state of HBO’s drama programming has not gone unnoticed in the industry and by TV commentators.

HBO already shook up its programming ranks in January with the departure of drama chief Michael Ellenberg and the promotion of former comedy exec VP Casey Bloys to president of series, late-night and specials. Rumblings about Lombardo’s future have been heard within HBO for several weeks.

Lombardo joined HBO in 1983. A lawyer by training, he rose through the ranks in business affairs. He was named exec VP of business affairs, production and programming operations in 2003. He was promoted to president of programming in 2007 as part of the broader management realignment after the departure of Chris Albrecht as chairman-CEO.