When it comes to seeking support or backing for an event or cause, there are many alternative phrases that can be used instead of the term "be sponsor for". These include phrases such as "support financially", "provide funding", "facilitate marketing", "offer promotional assistance", "back up", "endorsing", "providing resources", "underwriting" and "sustaining". Each of these phrases can be used in place of "be sponsor for", depending on the context and the intended tone of the message. By choosing the right phrase, you can convey the level of support and commitment you are looking for in a way that resonates with your target audience.