Argentina's government on Wednesday re-privatized the management of most of the passenger railway lines serving the capital region, but under much stricter supervision.

Two of the commuter lines in Greater Buenos Aires - Mitre and San Martin - will be operated by Roggio, one of Argentina's largest infrastructure groups and the majority shareholder in Metrovias, which manages the Buenos Aires metro.

The Belgrano Sur and Roca lines will be operated by the Emepa group, according to a document signed by Interior and Transportation Minister Florencio Randazzo.

Emepa is part of the UGOFE consortium of Argentine companies the government created in 2005 after revoking the concession it awarded to the Metropolitano consortium in 1994 as part of a railway privatization.

The five lines were later placed under the management of the SOFSE state-owned company last year.

The Sarmiento line, where accidents that have left 54 dead and hundreds injured over the past two years have occurred, will remain under state control.

"We've put in place a new operating regime that requires companies to present annual plans with respect to train frequency and maintenance, station cleaning and service quality," the minister said.

"In that regard, we've established a strict penalty regime that sanctions them in the event they do not meet these guidelines," including the revoking of concessions in the event of violations that put passengers' lives at risk, Randazzo said.

"At President Cristina (Fernandez de) Kirchner's request, we're undertaking an ambitious plan to renovate the metro area trains, which includes the arrival of more than 1,000 new cars this year and a major investment in infrastructure," the minister added.

In February 2012, 51 people died and more than 700 others were injured on the Sarmiento line when a train slammed through the buffers at Buenos Aires' busy Once station.

Sixteen months later, a passenger train collided with another train, which was empty at the time, on the capital's western outskirts. That accident, also on the Sarmiento line, left three dead and more than 300 injured.

Argentina's most recent railway crash occurred in November and left 80 people injured. EFE