It is used when someone is speaking on someone else's behalf or acting in their stead.
Here are some examples:
* "Hablando por mi equipo, queremos agradecerles su apoyo." (Speaking on behalf of my team, we want to thank you for your support.)
* "No puedo asistir a la reunión, pero mi colega estará hablando por mí." (I can't attend the meeting, but my colleague will be speaking on my behalf.)
* "Hablando por la empresa, les damos la bienvenida." (Speaking on behalf of the company, we welcome you.)
It's important to note that "hablando por" doesn't necessarily mean the speaker is authorized to act for the other person, but rather that they are expressing their thoughts or opinions on their behalf.