* GENCO to offer 350 mln new shares each to Superblock, TFD
* GENCO shares surge 22 pct on stake sales plan (Recasts with GENCO comments)
May 15 (Reuters) - Thai waste management company General Environmental Conservation PCL (GENCO) said it is selling a 33 percent stake to two domestic firms for around $42 million to grow its biomass power business, sparking a 22 percent jump in its shares.
GENCO said in a statement on Friday it will offer 350 million new shares, or 16.3 percent, at 2 baht each to a unit of Superblock PCL and a similar quantum to Thai Factory Development PCL in an estimated transaction worth a combined 1.4 billion baht ($42 million).
Thai Factory and Super Earth Energy Co Ltd, the unit of Superblock which is buying the stake, do not have any relationship with each other and are not required to make a compulsory offer to buy the remaining shares of GENCO, the company said.
Superblock said in a separate statement the transaction, expected to be completed by March 2016, will help the company to expand into new power business and it has no plan to buy more than 25 percent of GENCO.
GENCO is provider of industrial waste treatment services and has diversified into renewable energy such as waste and biomass power plants. Superblock has interests in electricity generation and information technology businesses, while Thai Factory is a developer of industrial factories and biomass power plants.
GENCO's shares, valued at $87 million before Friday's jump, soared 22 percent to 3.56 baht on Friday, resuming trading after being suspended on Thursday. ($1 = 33.50 Baht) (Reporting By Khettiya Jittapong; Editing by Muralikumar Anantharaman)