TLI stock rose 0.63% at the opening the bell but quickly lost ground in line with the broader market , which was down 0.2% by 0330 GMT.
The shares were priced at 16 baht, raising at least 34.4 billion baht ($937 million), from the sale of 2.3 billion shares, with about half from investors who bought before the deal went public, according to regulatory filings.
"Today's listing will help Thai Life grow with strength and we will use the funds to improve business efficiency and service for customers," chief executive officer Chai Chaiyawan said before the opening bell.
The volume of capital markets deals, especially IPOs, has fallen sharply in 2022 in Asia as global financial markets remain roiled by geopolitics, rising interest rates and ongoing uncertainty caused by Chinese regulatory upheaval.
Thai Life's flat opening was a reflection of high valuation and broader market performance, analysts said.
"This was a very weak showing for such a high profile IPO, reflecting the high IPO price and generally weak market sentiments," said M Corp Review analyst Athaporn Arayasantiparb.
Thailand's economy was among the slowest to recover in the region, according to the latest report from the Asian Development Bank.
TLI has the third-largest market share among Thai insurers. It plans to use the funds to invest in digital transformation and strengthening partnerships. It competes with market leaders AIA and Muang Thai Life Assurance.
TLI is Thailand's biggest IPO since microfinance firm Ngern Tid Lor went public last year, raising 38 billion baht.
The IPO has been the largest equity capital market deal in Southeast Asia in 2022, according to Refinitiv data. There were $2.45 billion worth of IPOs in the region in the first half of 2022, compared with $6.1 billion in the same period last year.
($1 = 36.7000 baht)
(Reporting by Chayut Setboonsarng in Bangkok and Scott Murdoch in Hong Kong; Editing by Ed Davies and Bradley Perrett)
