Some articles on the subject:
J. M. Sasson, "Circumcision in the Ancient Near East," JBL 85 (1966), pp. 473-476.
N. Wyatt, "Circumcision and Circumstance: Male Genital Mutilation in Ancient Israel and Ugarit," JSOT 33 (2009), pp. 405-431.
The Bible itself states that circumcision was widely practiced in the ANE by many nations, including the Egyptians:
" 'The days are coming,' declares Yahweh, 'when I will punish all who are circumcised only in the flesh — Egypt, Judah, Edom, Ammon, Moab and all who live in the wilderness in distant places [i.e. the Bedouin]. For all these nations are really uncircumcised, and even the whole house of Israel is uncircumcised in heart' " (Jeremiah 9:25-26).
There is however quite a bit of evidence that non-Israelite circumcision did not involve amputation of the foreskin but an incision and retraction of the skin flaps (see Richard Steiner's 1999 JBL article). Israelite circumcision was originally a rite of marriage; only later, probably in the exilic period, did it become a general practice for infants and eventually as a marker of Jewish identity.