Shares in Demco Pcl hit their all-time high after the company won a contract to build solar farms worth 2.2 billion baht ($73.6 million) for Rojana Industrial Park Pcl .
At the midsession break of 0530 GMT, Demco shares were up 5.3 percent at 12 baht, climbing at one point to 12.1 baht. The SET index was up 0.33 percent.
Rojana shares gained 0.7 percent to 13.8 baht.
The construction firm would book most of revenues from the solar project construction this year, starting from the first quarter, while Rojana would sell solar power from the second quarter of 2014, broker DBS Vickers Securities said in a note.
1308 (0608 GMT)
(Reporting by Viparat Jantraprap in Bangkok; Editing by Jijo Jacob)