SST and subsidiary Mudman Co Ltd bought all 969,900 shares of Greyhound Co Ltd, the high-street Thai fashion brand, and all 107,843 shares of Greyhound Café Co Ltd, the operator of the café chain with the same name.
The shares of both companies have par value of 100 baht each.
SST will pay 1.26 billion baht in cash to the existing shareholders. The remaining 588 million baht will be paid by 1.32 million Mudman shares, valued at 444.62 baht each and representing 15.67% of Mudman's paid-up capital, SST told the Stock Exchange of Thailand (SET) on Tuesday.
To finance the deal, Mudman raised its capital and sold 787,186 new shares to Khon Kaen Sugar Industry Plc (KSL) at 444.62 baht each, totalling 350 million baht, its parent company said in the statement.
It will also get loans from banks and existing shareholders of the acquired companies.
SST expected the deal to help it expand abroad and have its own brand in addition to its franchised businesses.
The deal will also help it diversify into the fashion business.
SST has three core businesses. Mudman, its food and restaurant unit, runs the franchised brands Dunkin' Donut, Au Bon Pain and Baskin' Robbins ice-cream.
It also operates document and property storage, rental service and space management for warehousing.
As well, it makes vegetable cooking oil under the Tip brand as well as animal feed and trade agricultural crops and products.
SST's major shareholders as of May 8, 2014 were the Sukhanindr and Chinthammit families.
Owned by Bhanu Inkawat, a famous designer, the 34-year-old Greyhound has 17 fashion stores in Thailand. It also exports apparel to overseas market such as South Korea, Singapore, and Indonesia.
Greyhound Café debuted 18 years ago. It now has 10 branches in Thailand, five franchised diners in Hong Kong and two in China under the Greyhound Café, Another Hound Café, Sweet Hound and Ground-hey brands.
Mr Bhanu remains a director of both companies after the acquisition.
SST shares closed on Tuesday at 22.10 baht, down 7.92%, in trade worth 295.08 million baht while those of KSL fell 0.70% to 14.10 baht in trade worth 18.35 million baht against the 1.15% decline of the main SET index.