By Suchitra Mohanty and Krishna N. Das
NEW DELHI (Reuters) - India's top court rejected petitions on Friday seeking an investigation of fighter jet deal worth about $8.7 billion with France's Dassault Aviation, handing a political victory to the ruling party months before a general election.
The ruling is a setback for the opposition Congress party, which had accused Prime Minister Narendra Modi's government of corruption in the deal to buy 36 Rafale planes and a decision to pick Reliance Defence as a domestic partner.
Reliance, owned by billionaire Anil Ambani, has no aeronautical expertise and was chosen ahead of state-run Hindustan Aeronautics, which has a history of making planes.
Dassault said in October it picked Reliance as a partner on its own, countering a French online media report that said the Indian government insisted on the firm as a condition of the contract.
The petitioners, two former ministers of Modi's Bharatiya Janata Party (BJP) and an activist lawyer, had argued that the escalating price of the deal should be investigated.
"We don't find any material to show that it's commercial favouritism," Chief Justice Ranjan Gogoi said in delivering the court's ruling.
"It's not proper for the court to examine each aspect of this case. It isn't a job of the court to compare pricing details," he said.
Congress used the issue to put pressure on Modi in recent state elections and ahead of a general election due by May. The BJP lost power in three heartland rural states in results announced this week.
The government and Reliance have said the charges are baseless.
Senior Congress leader Anand Sharma told reporters the party did not agree with the court ruling and demanded a parliamentary investigation into what he called an "arbitrary deal".
Finance Minister Arjun Jaitley, the BJP government's chief trouble-shooter, rejected the demand from Congress saying any investigation by a political body would be "partisan".
Several other BJP ministers and leaders took to Twitter to attack Congress, accusing it of politicising a deal the government says is critical for India's defence.
They also demanded an apology from Congress President Rahul Gandhi.
"Truth always triumphs!" BJP President Amit Shah tweeted.
"The court's judgement on the Rafale deal exposes the campaign of misinformation spearheaded by the Congress president for political gains," he said.
Ambani said the ruling showed "the complete falsity of the wild, baseless and politically-motivated allegations levelled against Reliance Group and me personally".
(Reporting by Suchitra Mohanty and Krishna N. Das; Writing by Sanjeev Miglani; Editing by Paul Tait and Darren Schuettler)