SEOUL, April 8 (Reuters) - About 5.25 million shares in Samsung Electronics are being offered in a block deal worth up to $330 million, according to a term sheet seen by Reuters on Monday.

The shares are being offered by Lee Boo-jin, a sister of Samsung Electronics Chairman Jay Y. Lee, the Seoul Economic Daily reported citing unnamed investment banking sources.

(Reporting by Scott Murdoch and Joyce Lee; editing by Jason Neely)