The offering is aimed at strengthening the company's financial structure towards building a sound foundation in the long term.
The subscription period is tentatively set for November 26-28, 2019.
TRIS Rating has rated Thai Union A+ with stable outlook and A- for its subordinated perpetual debentures.
The company decided to issue "subordinated perpetual debentures of Thai Union Group Public Company Limited No 2/2562. Payable upon liquidation with the issuer's call option and unconditional interest deferral", it said in a statement.
In addition, Thai Union retains the right to call the debentures after five years or upon other conditions in accordance with the terms and conditions of the debentures as specified in the prospectus. The coupon rate is set at 5 per cent a year for the first five years and will be payable quarterly.
The subordinated perpetual debentures will be offered to retail and/or institutional investors.
Bangkok Bank, Krung Thai Bank, Siam Commercial Bank and Phatra Securities have been appointed joint-lead arrangers.
"In our more than 40-year history, we have built a strong and successful company with a global footprint and a portfolio of 14 brands around the world," said Thai Union CEO Thiraphong Chansiri.
"Issuing these debentures will allow us to not only further strengthen our financial footing, but continue expanding our business as we pursue a path of consistent, solid growth".