Samsung Electronics has sold out of initial stock of the Galaxy S8 Plus 128GB model in Korea, five days after pre-orders began, the company said.

The South Korean tech giant prepared 150,000 units for pre-orders of the Galaxy S8 Plus 128GB model, which only comes in jet black and has 6GB RAM compared to 4GB RAM of the Galaxy S8. Now initial stock has sold out, those who newly pre-order the phone will get the model as late as end of May, Samsung said.

The company also said it has sold a total of 620,000 units of the Galaxy S8 and S8 Plus in the country so far.

The new phones broke the firm's pre-order record by selling 550,000 units over the weekend.

Samsung is launching the Galaxy S8 Plus with 6GB RAM in Korea and China. Those who pre-order the model get Samsung Dex, the new docking station that allows the phone to be used like a PC with Bluetooth keyboard and monitors.

The company is offering unprecedented benefits for pre-ordering customers, including a Bluetooth speaker for free and a one-year warranty for repairs. They can also start using the phone as early as April 18 before official sales begin three days later.

Analysts expect the latest flagship phones to help Samsung reach record profits in the second quarter.