(Corrects number of Samsung employees in par 16 to around half a million, from more than 250,000)
* Seoul court agrees to grant special prosecutor warrant
* Lee sought over bribery scandal involving President Park
* Arrest may hinder Samsung's strategic decision-making - experts
* Samsung: "will do our best to ensure that the truth is revealed"
By Hyunjoo Jin and Joyce Lee
SEOUL, Feb 17 (Reuters) - Samsung Group chief Jay Y. Lee was arrested early on Friday over his alleged role in a corruption scandal rocking the highest levels of power in South Korea, dealing a fresh blow to the world's biggest maker of smartphones and memory chips.
The 48-year-old Lee, scion of the country's richest family, was taken into custody at the Seoul Detention Centre after waiting there overnight for the decision. He was being held in a single cell with a TV and desk, a jail official said.
Lee is a suspect in the influence-peddling scandal that led parliament to impeach President Park Geun-hye in December, a decision that if upheld by the Constitutional Court would make her the country's first democratically elected leader forced from office.
Shares in flagship Samsung Electronics Co Ltd fell 1.4 percent, while shares in Samsung C&T Corp, the de facto holding company of Samsung Group, were down 2.8 percent compared with the wider market's drop of 0.2 percent.
Prosecutors have up to 10 days to indict Lee, Samsung's third-generation leader, although they can seek an extension. After indictment, a court would be required to make a ruling within three months.
No decision had been made on whether Lee's arrest would be contested or whether bail would be sought, a spokeswoman for Samsung Group said.
Samsung and Lee have denied wrongdoing in the case.
"We will do our best to ensure that the truth is revealed in future court proceedings," the Samsung Group said in a brief statement after Lee's arrest.
The same court had rejected a request last month to arrest Lee, but prosecutors on Tuesday brought additional accusations against Lee, seeking his arrest on bribery and other charges.
"We acknowledge the cause and necessity of the arrest," a judge said in his ruling.
The judge rejected the prosecution's request to arrest Samsung Electronics president Park Sang-jin.
SENSITIVE TIME
While Lee's detention is not expected to hamper day-to-day operation of Samsung firms, which are run by professional managers, experts said it could hinder strategic decision-making at South Korea's biggest conglomerate, or chaebol.
Samsung has been in the midst of an ongoing restructuring to clear a succession path for Lee to assume control after his father was incapacitated by a heart attack in 2014.