* "Law & Order audience more than halved since 2002
* Last episode to air on May 24 with guest Lindsey Vonn (Adds Dick Wolf statement, TNT says not interested)
LOS ANGELES, May 14 (Reuters) - The verdict is in. TV network NBC announced on Friday it is canceling crime drama "Law & Order" after 20 seasons.
With its revolving regular cast and its guest celebrities, New York-based "Law & Order" drew its inspiration from real crimes and events, giving it a "ripped from the headlines" appeal.
As well as winning the 1997 Emmy for best drama series, "Law & Order" has generated spinoff series, video games, and international versions of the show that tracks a crime investigation, the arrest of a suspect and a prosecution.
The spinoffs will continue but audiences for the series have slipped this year to an average 7.3 million viewers per episode from more than 18 million in 2002.
The last episode, with guest star Olympic skier Lindsey Vonn, will air on May 24.
"Law & Order" currently ties with 1960s western "Gunsmoke" as the longest-running U.S. prime time drama, both boasting a 20-season run. Fox comedy "The Simpsons" is the longest-running TV series in prime time, now in its 21st season.
Jeff Gaspin, chairman of NBC Universal Television Entertainment, said the franchise created by Dick Wolf had added to the success of NBC and Universal Media Studios over the past two decades.
"The legacy of his original 'Law & Order' series will continue to make an impact like no other series before," Gaspin said in a statement.
Wolf, who had said he hoped to beat "Gunsmoke's" record, said in a terse statement on Friday. "Never complain. Never explain."
'MANY MEMORABLE PERFORMANCES'
New York Mayor Michael Bloomberg, who has appeared as himself in the show, said "Law & Order" had been a New York City institution, paving the way for more than 150 TV shows based there today and showcasing the city's versatility as a film setting.
"It also helped launch the careers of thousands of talented actors and featured many memorable performances -- although my cameos are not among them," Bloomberg said in a statement.
The list of actors who used "Law & Order" as a springboard for their careers included Fred Thompson, who ran unsuccessfully for the 2008 Republican presidential nomination, and Chris Noth who went on to star in the TV and movie series "Sex and the City." The current cast includes Jeremy Sisto, Anthony Anderson, Sam Waterston and Alana de la Garza.
NBC, which will present its new slate of programming for 2010-11 to advertisers in New York next week, said it was picking up the new drama "LOLA," ("Law & Order: Los Angeles") and has also renewed "Law & Order: Special Victims Unit" for a 12th season.
Fans of the original show, known to TV critics and producers at "The Mother Ship," are hoping that another network will pick up the show.
But cable channel TNT on Friday dismissed speculation that it would start carrying original episodes of "Law & Order".
"With this series, TNT is the buyer and NBC is the seller. TNT is not in ongoing discussions about picking up the series for first-run episodes," TNT said in a statement.
NBC is owned by General Electric Co (GE.N) but it is expected to be folded into a $30 billion joint venture with No.1 U.S. cable operator Comcast Corp. (CMCSA.O) in a deal awaiting U.S. federal government approval.
(Reporting by Belinda Goldsmith; Editing by Sandra Maler)