Rome, February 7 - Italy's antitrust authority (AGCM) on Thursday opened investigations into Alitalia after a flight operated by a partner carrier skidded off a Rome runway on Saturday. Separate criminal probes into the incident involving the Romanian carrier Carpatair are already underway. Now AGCM wants to establish whether Alitalia infringed the national consumer code in relation to information given to passengers on the stricken Saturday flight and other services operated by partner carriers or in code-sharing. The probe follows complaints by consumer watchdog association Codacons and internal checks. "Simulations (have shown that) information concerning the carrier that effectively operates a flight is only provided at the third stage of on-line booking and in very small lettering," the antitrust authority said in a statement. In addition AGCM will also look into the promotion and sale by Alitalia of certain products and services. Three passengers were injured on Saturday when a Carpatair flight skidded off the runway during landing at Rome's Fiumicino airport en route from Pisa. Alitalia is now under investigation for commercial fraud after allegedly deceiving customers by selling tickets marked Alitalia which were in fact for a foreign company. The Italian carrier has denied the charges.