I understand it is sort of a State-owned business, but it should be 国企 in Chinese, 央 does not make sense here, it seems. And in dictionaries and practical usage, the Chinese character 央 is not a word used singlehandedly, so it is hard to understand the real meaning of the phrase.
央 means 中央; 央企 is the shortened form of 中央企业.
In short, 国有企业 are owned by the country; among them, those owned by 中央 (central government), more specially, by 国务院国资委 (the State-owned Assets Supervision and Administration Commission of the State Council) are called 中央企业, those owned by 地方政府 (local government) are called 地方企业.
You can get a list of 央企 from 央企名录.
According to this link