A three-way competition to fly cargo to the International Space Station for NASA has ended, and the U.S. space agency is set to announce the winners on Thursday.

Incumbents Space Exploration Technologies and Orbital ATK are vying with privately owned Sierra Nevada Corp., which is developing a robotic, reusable miniature space plane known as Dream Chaser.

CBC News will livestream the news conference, scheduled for 4 p.m. ET, to unveil the winning bids.

Privately owned SpaceX, as the California-based company is known, and Orbital both currently ferry cargo to the space station aboard capsules.

NASA previously eliminated proposals from Boeing Co and Lockheed-Martin for space station resupply missions.

The U.S. space agency has said it intends to award multiple contracts, each including at least six cargo flights to the station, a $100-billion research laboratory that flies about 400 kilometres above Earth.