Central Group did not immediately respond to Reuters' requests for comment.

The IPO, first announced in July, comes after Thailand took the top spot in Southeast Asia in 2019 with $4 billion in fundraisings, according to Refinitiv data. A slew of large issues are in the pipeline for this year.

Two of the sources said Central Retail's IPO price band is likely to be narrowed to 40-43 baht per share but there is no decision yet. Sources said the company was expected to close out the cornerstone tranche and set the IPO's final price later on Wednesday or on Thursday.

Central Retail's IPO opens on Jan 29. It will offer 1.69 billion shares and an overallotment option of 169 million shares.

As part of its listing plans, Central Group is delisting its retail business, Robinson Pcl and offering a share swap to Robinson's existing shareholders.

By Anshuman Daga and Scott Murdoch