MR Chatumongol Sonakul, a former permanent secretary of the Finance Ministry and former governor of the Bank of Thailand, was elected leader of the Action Coalition for Thailand Party (ACT Party) at a meeting of the party's co-founders on Sunday.
Political scientist Anek Laothammatas, who was earlier tipped for the post, withdrew from the race.
Suthep Thaugsuban, the former leader of the now-defunct People's Democratic Reform Committee (PDRC) and a co-founder of the party, chaired the meeting to elect the leader and executive committee members of the party, which was founded on May 25.
Mr Suthep said he will be steadfast in standing by the people and serving His Majesty the King and the nation. He vowed he will not take any position in the party, but only work with the people to build up the ACT Party. He will not run in the election - either as a candidate on the party list or in the constituency system. However, he said, he will reserve the right as a party founder to make speeches at party forums throughout the country.
The meeting first discussed details of the party name, its abbreviations, logo and policies.
Mr Suthep then nominated candidates to sit on the party's executive committee, with MR Chatumongol as party leader; Tavisak Na Taguathung as secretary-general; Ms Juthathat Laothammatas as treasurer; Jomdet Treemek as party registrar; and Lt Gen Nanthadej Meksawat, Veerachai Khlaithong and Mrs Sumetta Sae Ko party executive committee members.
One of the party's founders nominated Mr Anek for the party leader post, but he declined the nomination. Mr Anek said MR Chatumongol is suitable for the post, considering his educational background and his record as a clean and straightforward official who dared to oppose the government to protect the interests of the country.
The meeting voted to endorse the party leader and executive committee members as nominated by Mr Suthep.
MR Chatumongol, 74, said after being voted party leader that the first thing he will do is to recruit more members to set up branches throughout the country.
He said the party will hold a general assembly, with the main objective of electing a permanent executive committee - with a four-year term - to prepare for the election and carry out long-term political activities.
'MR' is short for Mom Ratchawongse, a title denoting the holder as a descendant of the royal family.