* IPO prices at 27 baht/share, low end of indicative range
* Sees strong response from retail investors (Adds company comments, details on IPO, background)
BANGKOK, May 7 (Reuters) - Global Power Synergy Co (GPSC), the power unit of Thailand's top energy firm PTT Pcl, on Thursday set its IPO price at 27 baht a share in a bid to raise 10.1 billion baht ($303 million) to finance expansion across Southeast Asia.
GPSC President Noppadol Pinsupa said the company aimed to conclude deals to buy stakes in two gas-fired power plants in the second half of this year, part of its plans to tap rising power demand across the region.
It is also planning to develop and invest in other power plants in Thailand, as well as Myanmar, Laos, Cambodia and Indonesia, the company said in a statement.
Company official and financial advisers confirmed an earlier Reuters report on the price of the public offering. The price was at the low end of an indicative range of 27-28 baht, and represented price to earnings at 20 times.
The utility is offering 374.6 million new shares, a 25 percent stake, to the public.
"We have seen strong demand from retail investors and we will conclude the result of share subscription this evening," Varah Sucharitakul, executive director of Finansa Group, one of GPSC's financial advisers, told a news conference.
GPSC will have a market capitalisation of about 40 billion baht, Varah said, making it the fourth-largest Thai power producer by market value.
GPSC is a joint venture between PTT and its subsidiaries PTT Global Chemical Pcl and Thai Oil Pcl.
The company said it made total revenue of 23.9 billion baht in 2014, down nearly 10 percent on-year due to lower income from electricity sales contracts. But net profit jumped 36 percent thanks to higher gains from investments and lower financial costs.
Noppadol has said GPSC plans to invest 18 billion baht over the next five years on capacity expansion and acquisitions, aiming to more than double power generating capacity to 2,800 megawatts by 2019.
The IPO comes as Thailand's military government finalises a long-term power development plan to meet rapidly rising demand. Generation capacity will need to double to around 70,000 megawatts by 2036, the government says.
PTT plans to take two units in which it owns a stake public this year. The other is oil refiner Star Petroleum Refining Co, in which PTT owns a 36 percent stake, with Chevron Corp holding the rest. ($1 = 33.34 Baht) (Reporting by Manunphattr Dhanananphorn and Khettiya Jittapong; Editing by Simon Webb and Stephen Coates)