Foreign holdings of Samsung Electronics Co. have dropped to the lowest level in 19 months, data showed Thursday, amid the tech giant's stock buyback and unfavorable external conditions.

Offshore investors owned 50.5 percent of Samsung Electronics shares as of Tuesday, marking the lowest since April 22 last year when the figure came to 50.48 percent, according to data by the Korea Exchange.

Foreign stock ownership of the top-cap company on the main stock market here has been on the decline since July when it reached the yearly peak of 51.86 percent.

The selling spree is attributable to the company's plan to buy back its own shares to enhance shareholder value, according to market watchers.

On Oct. 29, the tech giant began repurchasing 11.3 trillion won ($96.87 billion) worth of shares, which is to last for one year.

All of the shares to be bought will be canceled. On the day until Wednesday, foreign investors offloaded 129.9 billion won of its shares.

"Investors seem to scrambling to lock in profits from earlier gains upon the better-than-expected buyback plan. After all, we've seen similar patterns that the repurchase triggers a selling binge by foreigners," said Lee Kyung-min, researcher at Daeshin Securities, adding the trend is likely to continue for the time being.

Though Samsung's third-quarter earnings soared 29.3 percent on-year thanks to strong chip sales and a weak local currency, growing uncertainties amid a prolonged economic downturn caused Samsung to lose its allure to offshore investors, according to analysts.

"As no specific growth momentum exists and worries over a U.S. rate hike linger, large-cap shares would be affected the most, leading the market to continue to go bearish," said Kim Yong-koo, an analyst at Samsung Securities Co.

Samsung Electronics closed 0.87 percent up at 1,281,000 won on the Seoul bourse on Wednesday. (Yonhap)