Nagarjuna, in his Ratnavali lists compassion as the 7th paramita. Granted that compassion is a key teaching of Mahayana, but has anyone seen another paramita list where there is a 7th one? This is excluding the final four that are found in the standard list of ten.
I have seen it somewhere explained that Upaya (Skilful Means) equals Compassion, in that it is an active form of Compassion. Har Dayal explains Seven Paramitas in Bodhisattva Doctrine in Sanskrit Buddhist Literature
, he says it is by far the most important of the four remaining ones, also with the emphasis on active Compassion.