Samsung's new foldable phone represents a challenge for Apple in the iPhone maker's luxury device market, Goldman Sachs warned clients.

The Galaxy Fold includes "a compelling form factor that only Samsung's foldable OLED technology can deliver," Goldman analyst Rod Hall told clients in a note Wednesday. "Should that form factor spark consumer interest we would expect Samsung to delay access to the technology for Apple. We see this as a potential problem for Apple this year though the lack of a device at this point drives us to reserve judgment."

The latest gadget from Samsung is the first consumer-ready foldable smartphone. Samsung, which revealed the phone on Wednesday, said the device can easily fit in a user's hand like a traditional phone but can expand to tablet size to watch videos. It has a hefty price tag: nearly $2,000.

Samsung's unveiling also came at a time when shoppers — and phone makers — are scrambling to find innovative features to justify increased prices in the $1,000 range for high-end consumer products. Apple shares fell 0.1 percent in premarket trading Thursday following the Goldman Sachs note.

"Just as with the very popular Motorola RAZR devices back in the featurephone era, we see foldable screens as a compelling form factor," Hall added. "We see this as challenging for Apple, who could find themselves with no access to the critical flexible OLED technology for which we believe Samsung has at least a two year lead over other display competitors."

Apple shares are little changed over the last 12 months. The stock is up 9 percent this year but still trail the overall market.

Samsung first made known a prototype of the Galaxy Fold in November, when it promised to bring the device to market "soon." The Galaxy Fold operates on a version of Google Android that automatically adjusts for both tablet and phone modes.

Samsung stock is up more than 20 percent in 2019, bouncing off decline of over 20 percent in 2018.

— CNBC's Todd Haselton contributed reporting.