The Corporate Sector or "CorpSec" was located at the front end of the Tingel Arm region. It was the core of the Corporate Sector Authority, and was located between Aparo Sector and Wyl Sector. Its located in the Outer Rim Territories.
The Corporate Sector was first formed in 490 BBY to free the Republic lawmakers and the Corporate moneymakers from their differences. The Corporate Sector originally had a few hundred systems all devoid of intelligent life. The corporations allowed to operate in the sector could purchase entire regions of space, but were supervised by the Galactic Republic. The Tynnans eventually became a key business partner in the Corporate Sector.
During Emperor Palpatine's reign over the galaxy the Corporate Sector expanded to nearly 30,000 star systems, and the Corporate Sector Authority was established to administrate the sector internally. At the time of the Battle of Endor, a huge new palace was being built for Palpatine in the sector; because of difficulties in communications, construction continued after his death, wasting much Imperial money.