BANGKOK (Reuters) - Thailand's largest petrochemical maker, PTT Global Chemical Pcl (>> PTT Global Chemical PCL) plans to invest $4.5 billion from 2014 to 2018, mostly on foreign expansion, its chief executive said on Thursday.

The amount is unchanged from previous estimates. The company will use its revenues for about $2.5 billion while the rest will come from bank loans or bond issues, Bowon Vongsinudom, president and CEO of PTT Global, told reporters.

"We recently raised $1 billion via a bond issue and whether we will sell more bonds or seek loan will depend on our study on large foreign investments," Bowon said.

PTT Global, 49 percent owned by top energy firm PTT Pcl (>> PTT Public Company Limited), is considering the possibility of overseas investments especially in Indonesia, China, Malaysia and Vietnam, he said.

The Thai firm has already joined Indonesian state oil and gas firm Pertamina to build a petrochemical complex in Indonesia with estimated cost of $5 billion.

(Reporting by Khettiya Jittapong; Editing by Miral Fahmy)

Stocks treated in this article : PTT Public Company Limited, PTT Global Chemical PCL