* U.S. regulator says Actos drug can raise risk of bladder cancer
* Says warning should be added to label
* France, Germany last week suspended sales of the drug
* Takeda shares down 1.1 percent vs 0.9 percent fall in Nikkei (Adds analyst comment, background, updates share price)
TOKYO, Jun 16 Japan's Takeda Pharmaceutical Co shares fell after U.S. regulators said Takeda's Actos diabetes drug can raise the risk of bladder cancer if used for more than a year and that a warning should be added to the top-selling drug's packaging.
Last week, France and Germany suspended sales of Actos over similar fears, and attention had shifted to the U.S. Food and Drug Administration, which oversees the biggest market for Actos.
"The FDA's action is extremely mild, when compared with the measures taken by France or Germany," said Jefferies analyst Naomi Kumagai. "The FDA is not taking Actos off the shelves or asking doctors to stop prescribing it. It is merely telling professionals to inform patients of the risk-benefit balance."
"This on its own will not have an immediate impact on sales. Still, it is certainly not a positive," she said.
Takeda's shares were down 1.1 percent at 3,670 yen after flirting with a three-month low, against the Nikkei's 0.9 percent fall.
The FDA, which is conducting an ongoing 10-year study of Actos, said that patients who had the highest cumulative dose of the drug had an increased risk of bladder cancer, but that Actos did not lead to an increased risk of bladder cancer in the study overall.
Takeda is set to lose patent protection for Actos in the U.S. market soon, and will be exposed to competition from generic pills next summer. It said in a statement that it would add the appropriate warnings.
Actos, which has captured close to $5 billion in worldwide sales for Takeda, is also under review by the European Medicines Agency, based in London. Its decision could have an impact on the FDA, analysts said.
Actos competes with Merck and Co's Januvia and Janumet, which uses a different mechanism. Actos belongs to the same drug class as GlaxoSmithCline's Avandia, which was pulled from the European market and had its use restricted in the United States last September, after studies linked it to heart risks.