1427 GMT - The Gulf's non-oil recovery is taking hold, but its sustainability depends on the Strait of Hormuz reopening for an extended period, Capital Economics' Nicolas Crittenden says in a note. The GDP-weighted Gulf whole-economy purchasing managers' index rose to 52.5 in July from 51.8 in June, according to Capital Economics. This reflected a rebound in the UAE, an easing downturn in Qatar and signs of recovery in Kuwait, while Saudi Arabia remained the strongest of the Gulf's four biggest economies. Crittenden says the initial reopening of Hormuz helped drive the pickup in activity, but whether the recovery continues will depend on whether current negotiations over reopening the waterway prove successful.