BARCELONA—Facebook CEO Mark Zuckerberg stayed away from this week’s Mobile World Congress, the telecom industry’s annual assembly, for the first time in four years. That lowered Facebook’s profile at the gathering but not its activity level. Behind the scenes, executives from the social network wooed telecom executives as hard as ever—but with proposals better tuned to the carriers’ own needs.

In a private suite away from the main convention floor, and at a cocktail party on Tuesday night, Facebook executives emphasized ideas such as mobile payments where the company could cooperate with carriers. One idea, pitched to carriers such as Globe Telecom, was using the carriers’ payments systems to handle purchases on either Facebook or Messenger for people in the developing world without credit or debit cards, telecom executives said.