By Kim Junghyun

Lee, 66, who led the country's biggest conglomerate for nearly 20 years, stepped down from his top roles in the group and flagship Samsung Electronics, the world's leading memory chip maker, after being indicted in April.

Lee would likely escape any prolonged jail time because judges have often been lenient towards corporate leaders convicted of white collar crimes on the view that putting them behind bars could hurt South Korea's economy.

"No matter how important and influential Lee Kun-hee may be, we cannot forgive illegal behavior," prosecutor Cho Joon-woong said at Lee's trial, adding the former chairman had harmed the company's global reputation and betrayed the trust of investors.

Prosecutors were also seeking a fine of 350 billion won ($350.1 million).

Under South Korean law, Lee could face from five years to life in prison.

At the hearing, a somber-faced Lee apologized for the incident.

"I will take full responsibility for everything, so please be lenient to the others (facing charges)," Lee said. "I feel very sorry for the public and Samsung employees."

Lawyers for Lee said the demand of seven years in prison was too harsh and sought leniency for someone they described as a hero in making South Korea a global economic power.

"The success of Samsung stems from the great management and leadership philosophy of Lee Kun-hee," one of his lawyers said.

Samsung group firms account for 20 percent of total market capitalization on the main board of the South Korean bourse The group has more than 250,000 employees and its annual revenues of $160 billion are around the size of Singapore's GDP.

A special prosecutor in January launched a probe into corruption allegations after a former top legal executive at the group said some of its top management hid money and kept a slush fund to bribe politicians, prosecutors and officials.

The prosecutor also indicted nine other top executives, but found no evidence to support the bribery allegations.

(Additional reporting by Rhee So-eui; Writing by Jon Herskovitz; Editing by Jonathan Hopfner and Alex Richardson)