PTT PCL, Thailand's top energy firm, said on Wednesday it aimed to raise 10 billion baht ($304 million) by selling about 25 percent of group company Global Power Synergy Co (GPSC) through an initial public offering (IPO).

The IPO will likely take place in the second quarter and GPSC will use the proceeds to finance capacity expansion, Surong Bulakul, chief operating officer of PTT's infrastructure business, told reporters.

GPSC plans to boost electricity generating capacity to 6,000 megawatts by 2025 from 1,800 megawatts now.

The power subsidiary may review the expansion plan given weakening demand in a slowing economy, Surong said.