By Lisa Richwine

LOS ANGELES (Reuters) - HBO's award-winning fantasy drama "Game of Thrones" has earned a new crown: the largest first-week DVD sales among any series in the cable network's history.

Season one DVD sales reached about 350,000 units in the first seven days following its March 6 release, the network said on Thursday. That pace ranks ahead of other popular HBO series including "The Sopranos," "Sex and the City" and "True Blood."

The DVD sales indicate strong interest in "Game of Thrones" ahead of the second season, which starts April 1.

The "Game of Thrones" news comes as HBO battles the backlash from its cancellation of the show "Luck," produced by series star Dustin Hoffman, after the death of a third horse on the show.

Game of Thrones" tells the story of clashes among seven noble families seeking control of the fictional medieval region of Westeros. The series is derived from the five best-selling novels by George R.R. Martin and became a hit when it debuted last year. The show averaged 9.3 million viewers during its first season, ranking fourth among all series in the network's history.

The series earned critical acclaim and a supporting actor Emmy for Peter Dinklage, who plays the clever but rude Tyrion, among other awards. HBO is a unit of Time Warner.

The program also set an HBO series record for sales of digital downloads from outlets such as iTunesapple, the network said, but it did not provide figures.

"What we are seeing is 'Game of Thrones' being a hit across all platforms-network, disc and digital," said Henry McGee, president of HBO Home Entertainment.

(Reporting By Lisa Richwine; Editing by Ron Grover and Bob Tourtellotte)