As you want I am here giving you list of the largest information technology consulting firms in the world.

List of Information Technology (IT) consulting firms:

Tech Mahindra
Cognizant Technology Solutions
Accenture
Syntel
KPMG
Sogeti
CGI Group
Xerox acquired ACS
T-Systems
Mindtree
Wipro Technologies
HP Enterprise Services
Getronics
Tata Consultancy Services
NTT Data
Altran
Deloitte Touche Tohmatsu
PWC
Genpact
iGATE
Hexaware
EPAM Systems
Larsen & Toubro Infotech
IBM Global Business Services
Atos
Infosys
HCL Technologies
Neusoft Group
MphasiS
Pactera
Science Applications International Corporation
Dell acquired Perot Systems
Indra
Tieto
Ernst & Young
Booz Allen Hamilton
Oracle Financial Services Software
Avanade
Globant
Unisys
WNS Global Services
Sopra Steria
Capgemini
Computer Sciences Corporation