Dayanadhi Maran on Wednesday took over as the Minister for Communications and Information Technology.
Senior ministry officials briefed the Dravida Munnetra Kazhagam leader, who had delayed assumption of office due to the row over allocation of portfolios.
DMK leader T R Baalu also assumed office as Minister for Shipping and Road Transport and Highways, saying his priority will be to develop infrastructure for rapid economic progress.
Road Transport and Highways Secretary Ajai Vikram Singh and Shipping Secretary D T Joseph welcomed Baalu at the Transport Bhawan.
"There is a quantum jump in economic and industrial growth in the country for which all our highways have to be upgraded to international level," he told reporters after taking charge.
Baalu said his other priorities include development of inland waterways and operational and financial efficiency of ports.