The three companies agreed to a purchase price that values Permata at 1.63 times its book value as of March 31, down from the earlier agreed multiple of 1.77 times, conditional upon the deal closing before June 30.
Asia-focused lender StanChart said it now expects its unit, which owned Permata stake, to receive a consideration of about $1.06 billion, down from the $1.3 billion estimated in December, citing the revised valuation, reduction in Permata's equity and depreciation of the Indonesian rupiah.
In December, Thailand-based Bangkok Bank agreed to buy an 89.1% stake in Indonesia's Bank Permata for about $2.7 billion, in the first major overseas acquisition for a Thai bank.
StanChart and Astra International jointly controlled Permata, each owning 44.56% in the bank that operates about 330 branches across 62 cities in Southeast Asia's biggest economy.
Standard Chartered on Monday also said the deal would increase the group's common equity Tier 1 capital ratio by about 40 basis points.
(Reporting by Shreya Mariam Job in Bengaluru; Editing by Shinjini Ganguli)
