Mobile Country Code (MCC) in Montenegro
 

I have a dilemma about MCC (Mobile Country Code) in Montenegro. Wiki puts it as 297 for all three GSM networks, whether other serious web sites put it as 220 for Pro Monte operator (MNC=02) and for T-Mobile operator (MNC=04). Only m:tel provider (MNC=03) seems to have MCC=297.
Thanks in advance to anybody who can help me clear the dilemma.

It seems that Serbia is 220, so I assume that might be left over from the countries being federated, and 297 the newer one

(or just a mistake based on similar reasoning)

Yes, Serbia is 220, but for Montenegro wikipedia puts 297 as MCC, while NationMaster.com puts 220 (MCC) -02 (MNC) for ProMonte and 220 (MCC) -04 (MNC) for T-Mobile.
Which one is right, wiki or nationmaster?

Thanks a lot

297 is the correct MCC for Montenegro. 220 was the code before Montenegro separated from Serbia on June 3rd, 2006.