Construction of the line is scheduled to begin in 2024, he added.
The state committee managing land traffic has given its approval for the MRTA to hire a consultant to design foundation pillars for the monorail route.
The 22.1-kilometre Brown Line will feature 20 stations and run from Nonthaburi Civic Centre eastwards across the river to Lam Sali intersection in Bang Kapi district.
The Bt48-billion project will be a public-private partnership with a concession term of 30 years.