اللَّهُمَّ إِنِّي أَعُوذُ بِكَ أَنْ أُشْرِكَ بِكَ وَأَنَا أَعْلَمُ ، وَأَسْتَغْفِرُكَ لِمَا لَا أَعْلَمُ
Translation 
O Allah, I seek refuge with You lest I should commit shirk with You knowingly and I seek Your forgiveness for what I do unknowingly.
Note: Shirk means to associate others with Allah in those things which are specific to Him. This can occur in:
(1) belief, e.g. to believe that other than Allah has the power to benefit or harm without the will of Allah, or that they are equal to him in status or the merit to be worshipped beside Him,
(2) speech, e.g. to swear by other than Allah, which is a type Minor Shirk,
(3) action, e.g. to bow, prostrate or to do any other acts of worship to other than Allah.
Note: Shirk means to associate others with Allah in those things which are specific to Him. This can occur in:
(1) belief, e.g. to believe that other than Allah has the power to benefit or harm without the will of Allah, or that they are equal to him in status or the merit to be worshipped beside Him,
(2) speech, e.g. to swear by other than Allah, which is a type Minor Shirk,
(3) action, e.g. to bow, prostrate or to do any other acts of worship to other than Allah.
Transliteration
allaahumma innee a‛oodhu bika an ushrika bika wa ana a‛lamu, wa astaghfiruka li maa laa a‛lam
Sources:
Al-Adab Al-Mufrad No# 716
