* Louisiana jury orders $6 bln damages from Takeda, $3 bln from Eli Lilly
* Plaintiffs' lawyer acknowledges not sure if damages will be upheld
* Takeda shares mark biggest one-day loss in five years (Updates with confirmation of verdict, adds details of damages)
TOKYO, April 8 (Reuters) - A U.S. jury ordered Takeda Pharmaceutical Co Ltd to pay $6 billion in damages over claims that it concealed cancer risks associated with its Actos diabetes drug, the plaintiffs' lawyer said on Tuesday.
The massive award was met with "stunned silence" in the packed Lafayette, Louisiana, courtroom, plaintiffs' lawyer Mark Lanier said.
Eli Lilly and Co, Takeda's co-defendant, was ordered to pay $3 billion in punitive damages.
Takeda, Japan's largest pharmaceutical company, said it disagreed with the verdict and would challenge it vigorously, including through post-trial motions and an appeal.
Takeda's shares fell as much as 8.8 percent to 4,396 yen after the verdict, hitting an eight-month low and marking their biggest one-day drop in five years.
Lanier acknowledged it was not certain whether the damages award would be sustained as the legal process continued.
"Nobody has gone out and bought a new home," he told Reuters.
"This is a conservative judge and a conservative court and she's very 'balls and strikes'. We're not under any grand illusion."
He added that the judge wanted post-verdict motions filed quickly but had set no precise schedule.
Last May, a U.S. judge had nullified a separate jury verdict for $6.5 million against Takeda after ruling that the plaintiffs had failed to offer any reliable evidence that Actos had caused cancer.
In the latest case, Lanier said the jury deliberated for only an hour and 10 minutes to deliver its verdict finding liability on all 14 questions, and another 45 minutes to come out with the multibillion dollar punitive damages.
The jury also ordered the payment of $1.475 million in compensatory damages in the suit.
The case is In re: Actos product liability litigation, U.S. District Court for the Western District of Louisiana, No. 11-MD-2299. (Reporting by Daniel Levine in San Francisco; Additional reporting by Ritsuko Shimizu in Tokyo; Writing by Edmund Klamann; Editing by Dominic Lau and Stephen Coates)