Indian Prime Minister Narendra Modi is set to name Amit Shah, the president of his Hindu nationalist Bharatiya Janata Party (BJP), as his new finance minister, according to several Indian media reports.

As Modi's right-hand man and long-time strategist, Shah showed his acumen as a strategist by masterminding the BJP's landslide spring election victory.

But there are questions about his lack of central government experience and financial background, especially at a time when growing signs of weakness in Asia's third-largest economy mean a trusted hand is needed at the finance policy helm.

Modi is expected to announce his cabinet within hours, after being sworn in on Thursday evening at an open-air ceremony outside the colonial-era presidential palace with some 8,000 guests including Bollywood stars and leaders of neighbours Bangladesh and Sri Lanka.

The BJP swept to victory in the national election, held over 39 days in April and May, and increased its majority in the lower house of parliament.

If the media reports are correct, Shah would replace Arun Jaitley, who wrote to Modi on Wednesday asking not to be considered for a ministerial position because of health problems.

Shah would be taking over the finance portfolio at a sensitive time. He will probably need to move quickly to stimulate an economy beset by weak farm incomes, slow jobs growth and falling sales of key consumer goods including cars and motorbikes.

This week, two major industrial bodies called on the new government to take steps to bolster a growth rate that slowed to 6.6% in the three months to December – the lowest in five quarters – and is expected to have dropped further to 6.3% between January and March.

Several investors and traders said they did not expect Indian markets to react much if Shan's appointment was confirmed as they believed his ability to get things done would offset his lack of financial experience.

"The hallmark of this government is that there’s more PMO (Prime Minister's Office)-driven strategy and guidance. So, to that extent, you don’t need a proper technocrat to run the finance ministry - you need someone who can get things done," said Jayesh Shroff, co-founder of investment advisory firm Cask Capital.

Others were more wary. "We have no clue of what this guy knows or his financial knowledge. The market will take some time to understand his views," said a trader at a private bank, who declined to be identified.

A senior debt manager said Shah could be a big asset in the job given his experience across many Indian states and the importance of revenue from the goods and services tax that was brought in in 2017. "That is all built on state-centre coordination," he said.

In the election campaign, Shah helped rouse the BJP's nationalist base and make up for the loss of key state elections in December. Part of his strategy included deftly exploiting national security fears.

India will also have a new foreign minister, with incumbent Sushma Swaraj, who has had health issues, sitting among the audience but not on the dais with Modi's new ministerial team.

In the federal Indian system of appointments, ministers are sworn in before their specific positions are announced.

A potential replacement for Swaraj could be former foreign secretary, S Jaishankar, who was on the dais. A former ambassador to the United States and China, Jaishankar led India’s diplomatic corps during Modi’s first term before retiring in early 2018 and subsequently joining the Tata Group conglomerate.

Shah and Jaishankar were not immediately available for comment.

Many other ministers who are also senior members of the ruling coalition are expected to retain their cabinet jobs.

But Modi, the 68-year-old son of a tea seller, could also promote fresh faces to reward a good performance in the seven-phase election.

He focused his election campaign on national security, after tension with old rival Pakistan surged in February over a deadly bomb attack on security forces in the disputed region of Kashmir, which was claimed by Pakistan-based militants.

Notably, the leader of Pakistan was not invited to the inauguration.

"India is proud of all those brave men and women martyred in the line of duty," Modi said after visiting a war memorial near parliament on Thursday.

"Our government will leave no stone unturned to safeguard India’s unity and integrity. National security is our priority."

The BJP controls 303 of the 545 seats in the lower house, which might tempt Modi to push for controversial land and labour reforms to help stimulate the economy.

Modi enacted reforms such as a goods and services tax and a bankruptcy law in his first five-year term, but faced criticism for failing to create enough jobs for people entering the job market, weak farm prices and tepid growth.

India's main opposition Congress party is trying to pick up the pieces after its second straight election loss.

Its president, Rahul Gandhi, has offered to resign. The party said on Thursday it would not let representatives take part in televised debates for a month while it analyses its defeat.

Deshsangbad/fh/mmh