JAKARTA (REUTERS) - An Indonesian court on Monday ruled that tycoon Aburizal Bakrie was the leader of the country's largest opposition Golkar party, dashing rivals' hopes the party would defect to the ruling coalition under a different leader.

Golkar, controls nearly 15 per cent of seats in parliament and has been embroiled in a leadership dispute for months. Some top party members have suggested joining President Joko Widodo's minority ruling coalition.

The dispute ended up in court and on Monday, Judge Satya Bakti told a hearing in Jakarta the court recognised Bakrie's leadership of the party.

Golkar Secretary General Idrus Marham, a Bakrie supporter, said the ruling meant the party would remain in opposition.

"From the start, we've been committed to the opposition and this decision confirms it," he said.

"We will stay outside the government but ... we have no intention to disrupt government."

Bakrie, patriarch of the family-owned Bakrie Group conglomerate, backed defeated presidential candidate Prabowo Subianto a presidential election last year.

But disgruntled party members mounted a bid to oust him when Golkar, the political vehicle of former authoritarian ruler Suharto, failed to make it into government for the first time ever.

The Ministry for Law and Human Rights in March issued a decree recognising Bakrie's rival as party chief, paving the way for Golkar to join the governing coalition.

A ministry spokesman declined to comment on Monday's court ruling.