That concession was then transferred to French-owned company "Sociedad Anónima Compañía del Ferrocarril Rosario a Puerto Belgrano" in December 1906.

The costs of construction were high so the railway required several engineering, for example the seven iron bridges that cross the Sauce Grande River, near Bahía Blanca.

The military port of Bahía Blanca received all the goods necessary for the construction of the railway, including rail tracks and even prefabricated home for employees, steam locomotives and coaches.

The company made the arrangements to get a concession to build an extension branch to Bahía Blanca and an access to Port of ingeniero White through a junction with Buenos Aires Great Southern Railway to freight services exclusively.

The company set headquarters in Villa Diego (Rosario) in 1909, where a passenger and freight station (named "Coronel Aguirre") was built.

Works were directed by Swiss Engineer Armin Reimman who died short after the line was inaugurated, being replaced by his colleague Lucien Capelle.

When the whole Argentine railway network was nationalised by the Juan Peron's administration in 1948, the RPBR line was divided into two sections, the north (from Rosario to Ingeniero Beaugey - Km.

With the railway privatisation led by President Carlos Menem in early 1990s, the R&PB line was granted in concession to freight rail transport company Ferroexpreso Pampeano.