Not through that partner. Permanent residence is not nationality, and an owner who is a United States permanent resident does not count toward the treaty-national half of the ownership. At least fifty per cent must sit with treaty nationals who are not United States permanent residents.
Count nationality, not residence
The arithmetic is unforgiving and it is worth doing before anything else is agreed. Add up only the percentages held by nationals of the treaty country, excluding any of them who hold United States permanent residence, and see whether the total reaches half. Where it does not, the remedies are commercial rather than clever: change the split, bring in another treaty-national owner, or restructure so that the treaty national holds the qualifying interest. Each of those has tax and partnership consequences that belong in the same conversation, which is why the cap table should be discussed with the accountant and the immigration adviser at the same table.
Hypothetical example: three people plan to buy a lumber and building-materials yard in the United States. A Canadian citizen from Roxton Pond takes forty-five per cent, a long-time neighbour who is an Italian citizen and a Canadian permanent resident takes thirty, and a United States citizen takes twenty-five. Canadian nationality reaches forty-five per cent, which is short. The neighbour’s Canadian permanent residence does not help, though his Italian citizenship might open a different analysis if that country appears on the current treaty list. Check the list, then decide the split deliberately rather than discovering it after closing.