Nafi' narrates from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that he used to begin Surah al-Fatihah with 'In the name of Allah, the Most Gracious, the Most Merciful' [Surah al-Fatihah: 1].
This is the correct version, as mawquf (the practice of Ibn Umar himself).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2402