SEOUL (Reuters) -Samsung Electronics has decided to buy back shares worth 10 trillion won ($7.17 billion) over a one-year period to boost shareholder value, after shares plunged to more than four-year lows earlier in the week.

Samsung Electronics Co. shares surged after South Korea’s biggest company announced a surprise plan to buy back about 10 trillion won ($7.2 billion) of its own stock over the next year.