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Delta’s investments in the customer experience are reaping rewards once again – this time in the form of recognition from Fortune and Travel+Leisure.

The airline was recognized as part of Fortune and Travel+Leisure’s second annual Best in Business Travel survey, taking the top spot in two out of the six categories: Best Airport Lounges and Best Business & First Class In-Flight Experience.

Delta has invested millions of dollars to enhance the look, feel and tastes in each of its 50 Sky Clubs around the globe. For more than a year it has been improving Delta Sky Club experience with additions including premium drink offerings, complimentary local craft beers, modern décor seating, locally inspired art and a chef-designed menu.

In the air, Delta has recently completed it enhancements to Delta One, which include full flat-bed seats with direct aisle access on all wide-body planes, Westin Heavenly In-Flight Bedding featuring a full-size pillow and quilted comforter, chef-designed cuisine and Master Sommelier Andrea Robinson's upgraded wine program and industry-leading “Delta Studio” including hundreds of complimentary movies, TV shows, songs and games, and an upgraded amenity kit featuring Tumi and MALIN+GOETZ products.

Delta came in fourth in the survey overall but finished ahead of the other three major carriers: American Airlines, United Airlines and Southwest Airlines.

In the survey, Fortune and Travel+Leisure asked readers about their habits and brand preferences while traveling for work. Respondents named their favorite airlines and rated them on a variety of criteria, including customer service, frequent flier programs, in-flight class experience, food and entertainment options, and airport lounges.