The two largest firms in India's Reliance group have reported slightly higher profits than expected ahead of their planned merger.

Profits at Reliance Petroleum, which operates the country's largest petroleum refinery, were up 5.3% in the period of January to March of this year.

Reliance Industries - India's largest petrochemicals company - saw profits rise 16.5% to $148m over the same period.

The company also confirmed that Mukesh Ambani would take over as chairman following the death of his father, group founder Dhirubhai Ambani, a month ago.

Younger brother Anil Ambani becomes vice chairman.

Mammoth merger

Reliance Industries said better product prices had pushed up its profits whilst Reliance Petroleum said its income had risen, mainly from its investments.

The planned merger of the two firms was announced in March but is awaiting clearance from a court in Gujarat state.

It will create India's first fully integrated energy company, and the third largest Indian company by value.

Analysts say the deal will bring the new combined entity tax benefits and improve its chances of gaining control of state-run refiners Hindustan Petroleum and Bharat Petroleum.