Mr Puchong said the endorsement of the winning candidates agreed at an EC meeting this morning.
The EC endorsed 58 candidates with the highest votes who had no complaint filed against them.
The 19 others were still under investigation because about 30-40 complaints were filed against them, mostly for alleged violation of the election law such as campaigning for votes beyond the legal limits, smearing other candidates in their speeches, and putting up campaign signs at prohibited spots.
Mr Puchong said the EC is still investigating the complaints.
The 19 senators-elect not yet endorsed are for Bangkok, Chaiyaphum, Nakhon Nayok, Pathum Thani, Phetchabun, Phrae, Mae Hong Son, Ranong, Lop Buri, Lampang, Lamphun, Si Sa Ket, Samut Prakan, Samut Sakhon, Sing Buri, Surat Thani, Nong Bua Lamphu, Amnat Charoen and Ubon Ratchathani provinces.
The senator-elect for Bangkok is Khunying Jaruwan Maintaka, a former auditor-general.