(Corrects to fix abbreviation in paragraph four to VLGCs)

* Details of IPO currently being discussed

* Company eyes fleet expansion, rejuvenation

* Company signs deal with Hyundai for 15 new tankers

JAKARTA, Jan 18 (Reuters) - Pertamina International Shipping (PIS), a unit of Indonesian state energy firm Pertamina, is considering an initial public offering (IPO) next year to help finance its expansion plan, a company official said on Thursday.

The details of the potential IPO are currently being discussed, corporate secretary Aryomekka Firdaus said.

"The targets in our long term plans would require us to secure relatively large funding, so an IPO is one of our options," he said in a text message.

The firm this month said it plans to add six very large gas carriers (VLGCs) this year to its fleet as it focused on gas transportation. It launched two of those VLGCs earlier this month.

PIS said in a separate statement on Thursday that it has signed a deal with Hyundai Mipo Dockyard to build 15 medium range tankers to help rejuvenate its fleet.

The additional tankers would cost around $700 million and will be delivered in stages until 2026, the company said in a statement.

Five of the new tankers, with capacity of 50,000 DWT, will be for the transportation of fuel. Five other vessels will transport crude oil and the remaining five will be for petrochemical products.

The bulk of the new vessels will be for the company's Asia Pacific business.

"This is an effort to develop (our) business and capture new opportunities in the market. Several similar vessels stationed in Singapore have been successfully utilized for the international third party market," Chief Executive Yoki Firnandi said in the statement. (Reporting by Fransiska Nangoy; Editing by Martin Petty and Jacqueline Wong)