In Muslim Arab countries before the abolition of slavery, Christian Arabs (and Jews) also could own slaves. They just couldn't own Muslim slaves.
BTW, slavery in Muslim countries was never race-based. Muslims have always been equal-opportunity enslavers. For centuries the Ottomans raided eastern Europe and the Barbary pirates raided European shipping and Mediterranean coastlines. Millions of "white" slaves were obtained in this way, to go with the millions of black slaves imported across the Sahara and up the East African coast.
For centuries the Ottomans raided eastern Europe and the Barbary pirates raided European shipping and Mediterranean coastlines...
I know—the Turks enslaved my ancestors. ANd when they could not any moe they genocided them.
As for your comment about abolition of slavery in Muslim countries - SLAVERY IS ALIVE IN WELL IN MUSLIM COUNTRIES TODAY!