(Adds background on project)

HOUSTON, March 19 (Reuters) - Occidental Petroleum Corp's first direct-air, carbon capture project is 70% complete, CEO Vicki Hollub said on Tuesday.

The first phase of the startup is expected in mid-2025. When complete, the Stratos project will be able to remove 500,000 tons of carbon from the atmosphere per year, she said in remarks at the CERAWeek energy conference.

The project has received a $550 million investment from BlackRock Inc and Occidental has signed deals to sell carbon removal credits from the plant to telecommunications giant AT&T, TD Bank and others.

"There are not enough carbon reduction credits to achieve what we want to, but hopefully we can get there by partnering with companies around the world that are trying to achieve the same goal," said Hollub.

(Reporting by Gary McWilliams)