Research firm iSuppli’s Top 10 Global EMS firms list, which came out today, differs in several respects from Circuits Assembly’s findings.

Why? It may be that the iSuppli data for Foxconn take into account non-EMS related sales (the company also produces bare boards and connectors, among other things). Even so, Foxconn itself last week reported 2008 revenues of $42.3 billion.

iSuppli also excludes Cal-Comp Electronics/Kinpo Electronics from its list, despite that company’s contract manufacturing revenues of $3.2 billion last year, which would place it seventh overall.

Finally, iSuppli includes Universal Scientific in its ranking, although the Taiwanese company reports EMS sales of just $490 million in 2008.