Facebook's proposed acquisition of mobile messaging startup WhatsApp was given the green light by the Federal Trade Commission on Thursday despite objections from two consumer privacy groups. Approval from international regulators is still needed before the deal is finalized but it's certainly a step in the right direction.

The approval came with an asterisk attached, however, as the FTC sent a letter to both companies regarding privacy concerns.

Jessica Rich, director of the Bureau of Consumer Protection at the FTC, noted in the letter that WhatsApp has made a number of promises about the limited nature of the data it collects, maintains and shares with third parties. The promises in question exceed the protections currently promised to Facebook users and must remain in place regardless of the outcome of the acquisition.

In the event that the acquisition is completed without incident and WhatsApp fails to make good on those promises, both WhatsApp and Facebook could be in violation of the Federal Trade Commission Act.

Furthermore, WhatsApp must also adhere to a previous agreement that Facebook made with the FTC that requires them to notify consumers and obtain consent before sharing information beyond their privacy settings.

In a statement on the matter, a Facebook spokesperson told PCWorld they were pleased the FTC has completed its review and cleared the acquisition. The rep added that both companies will continue to comply with all applicable laws after the transaction closes.