The phrase "to propose a partnership" means to suggest or offer the idea of working together with another person or organization towards a common goal or project. Full definition
Apple had even considered proposing a partnership with Amazon, «with iTunes acting as «an e-book reseller exclusive to Amazon and Amazon becom [ing] an audio / video iTunes reseller exclusive to Apple,»» Cote wrote. (arstechnica.com)
Involvement with an international school also helps these organizations increase their public profile; sometimes these projects work in the exact neighborhood of these schools, but were unrecognized until someone within the school proposed a partnership, resulting in increased visibility for the project within the community. (globaleducationmagazine.com)