Which organization should own partner portal and marketing tools?

Marketing, so long as your marketing organization clearly recognizes that Sales is their customer. In any for-profit company, the people who lead the charge to sales should be able to spend the maximum proportion of their time actively selling. Marketing is there to provide the messaging, the promotional support, the “air-cover,” and the back-end operations needed to support the sales team in their efforts to capture more sales. PRM, partner portal, marketing tools, and more are all resources marketing should be managing. Marketing should make the output of all of them easily and readily available to salespeople.