Howard T. Owens (National Geographic Channel)

In a major restructuring of the executive suite at Washington-based National Geographic Channel, Howard T. Owens, a founding managing director of Reveille Productions — the company behind NBC’s “The Biggest Loser,” Fox’s “MasterChef,” Bravo’s “Blow-Out,” NBC’s “The Office,” and Showtime’s “The Tudors” — has been named new president of the National Geographic Channels US.

Owens succeeds Steve Schiffman, who will stay at the network through a transition period.

HBO marketing exec Courteney Monroe has been named to the newly created post of chief marketing officer for U.S. channels at NatGeo. She will assume the post in January. Kiera Hynninen, who has been the network’s senior marketing executive since 2007, is leaving.

Last month, Monroe announced she was relocating full-time to Washington and stepping down at HBO, where, as EVP of consumer marketing, she was responsible for every aspect of the pay cable network’s brand and marketing across all platforms. Since Monroe’s husband had taken a job in Washington last summer, she had been commuting between Washington and New York.

Courteney Monroe (National Geographic Channel)

Meanwhile, Michael Cascio, NatGeo Channel’s senior vp of production, has been promoted to exec vice president for programming for National Geographic Channel U.S. He will oversee all aspects of the network’s programming strategy and content, including development, production, and scheduling.

Geoff Daniels remains senior vp for the channel Nat Geo WILD.

And, Chris Albert has been upped to senior vp communications worldwide and talent relations at NatGeo; replacing Russell Howard, senior vp communications.

All three departing execs have contracts that are set to expire within the next six months, according to a company rep.

Owens, who will relocate from Los Angeles to Washington, will oversee programming, development, communications, research, and business affairs. Owens and Monroe will report to David Lyle, the recently named CEO of National Geographic Channels US and Global Programming.

Cascio, a onetime Discovery Communications programming exec, will report to Owens.

The moves aren’t entirely unexpected; just last August, Lyle was brought on board as new CEO with a mandate from the board to take the channels to the next level. (Before coming to Washington to take that post, he had been head of Nat Geo Channel’s west coast development office since March.)

Though he said at the time of his appointment he was delighted he would be working with “a great team that I’ve come to know and respect over the past few months,” and that he felt “fortunate to be able to lead a group that consistently delivers top-notch nonfiction programming that resonates with audiences,” you could smell change in the air. Maybe that’s because, before being named west coast development guy for NatGeo, Lyle had worked at Fox and had most recently been president of Fox Look, a unit that specialized in international licensing and production of reality formats, as well as the Fox Reality Channel. Lyle’s resume also includes posts at FremantleMedia, where he was involved in the launch of Fox broadcast network’s hit singing competition series “American Idol,” and at Australia’s Nine Network.

“I have known Howard for more than a decade, and I am confident he is the right person at the right time to take our network into our next era,” Lyle said Friday of the appointment.

Prior to Reveille, Owens was an agent with the William Morris Agency, where he worked in the corporate consulting and television packaging divisions.

Meanwhile, NatGeo’s been without a head of legal and business affairs since the recent departure of Mike Beller; those responsibilities are currently being run out of the west-coast offices of Fox Cable Networks. National Geographic Channel is a joint venture between News Corporation’s FCN and National Geographic. It’s based at National Geographic Society headquarters in Washington.

This past summer, NatGeo Channel, which launched in January of 2001, scored the highest rated summer in its history. Just last week, Nat Geo’s new WILD channel enjoyed its most viewed total day.

In October, NatGeo Channel averaged about 448,000 viewers in primetime -- up 27 percent over same month last year. For comparison sake, Silver Spring-based Discovery Channel, averaged nearly 1.1 million this past October in primetime.

NatGeo Channel’s programs include “Explorer,” “Border Wars,” “Alaska State Troopers” and “Rocket City Rednecks.”