SET-listed Thai Union Frozen Products Plc (TUF) will raise funds through a new share issue totalling US$400 million.
Proceeds will be used to finance its purchase of California-based Bumble Bee Foods in a deal worth $1.5 billion.
The preferential public offering will be open to existing shareholders under a ratio that will be finalised later.
The fundraising plan will be submitted for shareholder approval at the annual general meeting on April 3.
The world's top exporter of canned and frozen tuna and shrimp posted a 2014 net profit of 5.1 billion baht.
TUF shares closed yesterday on the SET at 21.40 baht, down 70 satang, in trade worth 706 million baht.