Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) led one group of his Companions in two rak'ahs, then gave the salam; then he led the other group in two rak'ahs and gave the salam.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5108