The June timing of the initial public offering (IPO), which would be the largest in Southeast Asia so far this year, has not been reported previously. Pertamina Hulu in February delayed its IPO plan over an administrative issue, Indonesia's financial regulator said, without giving a new timeline.

The planned listing of Pertamina Hulu comes amid a drive by the Indonesian government to privatise some state-owned enterprises and to enhance energy security.

At $1.36 billion, the IPO would surpass the recent $680 million float of Indonesian nickel company PT Trimegah Bangun Persada on April 12.

The last time Indonesia had an IPO of more than $1 billion was in April 2022, with the listing of tech firm GoTo.

Indonesia's IPO market has raised $1.58 billion so far this year, second only to China in the Asia-Pacific region excluding Japan and ahead of traditional powerhouse Hong Kong, according to Refinitiv data.

Pertamina Hulu plans to use the proceeds to expand oil production via acquisitions or drilling of new wells, one of the sources said. They declined to be named because they were not authorised to speak publicly about the matter.

The company did not respond immediately to a request for comment.

Pertamina Hulu was expected to sell a 10% to 15% stake in the offering, a government minister said in December.

Citigroup, Credit Suisse and JPMorgan are joint bookrunners of the IPO, along with Indonesia's BRI Danareksa and Bank Mandiri, according to a term sheet seen by Reuters in March.

($1 = 14,700.0000 rupiah)

(Reporting by Scott Murdoch in Sydney and Yantoultra Ngui in Singapore; Additional reporting by Bernadette Christina Munthe in Jakarta; Editing by Jamie Freed)

By Scott Murdoch and Yantoultra Ngui