Bajwa is taking over from Vanitha Narayanan, who has been elevated as the chairman.
"By constantly reinventing itself and investing in innovation, IBM today is in a sweet spot to help businesses and governments with their digital transformation journey," said Bajwa in a statement.
Karan joined IBM last year as an executive for strategy and transformation in the Asia-Pacific region. Before this, he was leading India business and Cloud Transition at Microsoft.
Before this role, Bajwa had worked for five years with IBM and spearheaded networking business till 2005. He will be responsible for all strategic and operational matters related to IBM's sales, marketing, services and delivery operations in the India/SA region, including Bangladesh, Nepal and Sri Lanka. He will lead the team to win new business, shape market opportunities by building alliances and partnerships and solidify the company's position in the marketplace. He will lead IBM's partnership with clients for a cloud and cognitive led digital transformation of their businesses.
As chairman, Narayanan will play a critical role in enabling capabilities across IBM's global missions in India, global centres of excellence, research and innovation labs.
Both Bajwa and Narayanan will report to Randy Walker, Chairman, IBM Asia-Pacific. These appointments are effective immediately, the firm said in a statement.