The ad, broadcast only in the United States, comes two days before its Galaxy Z Flip phones, which open and close vertically like a flip phone, are due to be unveiled at an event in San Francisco.

While there were many shots of the phones, which come in at least purple and black, there were few other details.

They are, however, expected to be less expensive than the $1,980 (£1,535.5) Galaxy Fold which opens like a book and was launched in September, delayed by several months after problems with its screens.

"The new Galaxy Z Flip foldable phone will create a halo effect for Samsung's brand and help it better compete with Apple's pricey models," said Tom Kang, an analyst at research firm Counterpoint, adding that Samsung had taken the lead in foldable phones at a time when Chinese rivals looked set to leap into the nascent market.

(Reporting by Hyunjoo Jin; Additional reporting by Stephen Nellis in San Francisco; Editing by Edwina Gibbs)

By Hyunjoo Jin

Stocks treated in this article : Apple Inc., Samsung Electronics Co Ltd