The new design would include fewer stations than originally envisioned, but would also increase connections with the rest of the network.
Some 12 firms made bids for two contracts, entailing work on 50km of the highway in San Juan province.
The study is to structure a public-private partnership project for the Barberena bypass.
The case involves the project to expand the Arraiján-La Chorrera highway, which was completed during the government of former president Ricardo Martinelli.
The concessionaire suspended services because the due to the lack of payments.
President Juan Carlos Varela had requested that the project be completed by January 2019 when the country is set to host World Youth Day, a large international Catholic event.
The Brazilian firm will not be allowed to bid in public works processes for a year, as the company is under investigation over alleged corruption practices.
However, the transport ministry reportedly opposes the idea.
Only two of the offers received exceeded the reference price set by the Veracruz port authority.