United Parcel Service, UPS, Amazon In this Oct. 18, 2010 photo, Amazon.com boxes await delivery in a UPS truck in Palo Alto, Calif. Online retailer Amazon.com Inc. is set to report its fourth-quarter results after the close of trading on Wall StreetEarns Amazon, Palo Alto, USA

Antitrust regulators approved Amazon’s planned $13.7 billion acquisition of Whole Foods shortly after the grocer’s shareholders voted to approve the deal.

The shareholders met at the grocery chain’s headquarters in Austin, Tex., early on Wednesday, and later that day, the Federal Trade Commission’s acting director of its competition bureau, Bruce Hoffman, effectively approved the deal by ending a cursory investigation into any antitrust implications.

“Based on our investigation we have decided not to pursue this matter further,”Hoffman said. “Of course, the FTC always has the ability to investigate anticompetitive conduct should such action be warranted.”

Even though the transaction itself doesn’t raise obvious antitrust red flags, there have been growing concerns over what effect the merger might have on other grocery stores.

The current plan is for completion of the transaction by the end of 2017. The deal is still subject to other customary closing conditions.

Amazon said in June that it would pay $42 a share in an all-cash deal that includes Whole Foods’ debt. The grocery chain, which has sales of $16 billion, has 460 stores across the U.S., Canada and the U.K. Employees total 87,000 in number.

When the proposed transaction was announced on June 16, Whole Foods cofounder and chief executive officer John Mackey said, “This partnership presents an opportunity to maximize value for Whole Foods Market’s shareholders, while at the same time extending our mission and bringing the highest quality, experience, convenience and innovation to our customers.”

Mackey is slated to continue as ceo of the grocery chain, and its headquarters is expected to remain in Austin.

Amazon has been expanding into different categories. It recently launched its own private-label brands, has inked deals with big names such as Nike and set up a box delivery program called Prime Wardrobe.

The e-commerce market platform hasn’t had much success in the grocery business. The thinking among some is that Amazon could use some of the space in Whole Foods to provide space for either showcasing select items available at Amazon.com or for pick-up to help expand its same-day delivery distribution network. Others think Amazon might leave the business as is for now as it learns from Whole Foods how it manages day-to-day operations in a brick-and-mortar setting.