Final answer:
The Northwest-Delta merger was completed on January 31, 2010, creating one of the largest global airlines after fully combining operations under the Delta name.
Step-by-step explanation:
The Northwest-Delta merger refers to the integration between Northwest Airlines and Delta Air Lines, one of the largest airline mergers in history. This corporate event officially completed its integration process on January 31, 2010.
From that date forward, the Northwest Airlines operations were fully combined under the Delta name, leading to a single airline operating under the Delta Air Lines Certificate of Public Convenience and Necessity. This integration created one of the world's largest global airlines, influencing prices, routes, and the international aviation market.