Siemens said Thursday it was ready to discuss compensation for Brazil's Sao Paulo state should it be proven the German engineering giant engaged in price-rigging during bidding for urban rail systems.

"Siemens is ready to discuss an accord to pay compensation once the evidence presented is proven by competent authorities," the daily Estado de Sao Paulo quoted Paulo Stark, chief executive of Siemens' Brazilian branch, as saying.

Stark told a Sao Paulo municipal chamber's enquiry panel that Siemens had turned over evidence of "possible cartel formation that must be probed by authorities."

He said the investigation would establish whether "an illegal act" occurred. "Until then it is all speculation," he noted.

In August, the German company pledged full cooperation with Sao Paulo authorities after being hit with a civil suit linked to the alleged price-fixing during bidding for the city's metro rail systems from 1999 to 2009.

State prosecutors launched an investigation based on documents from Brazil's antitrust authority CADE.

Sao Paulo officials said at the time that Siemens was targeted because it confessed to its role in the price-rigging cartel.

Several other foreign firms were also alleged to have been involved in the price-rigging scheme, including Spain's CAF, Japan's Mitsui, Bombardier of Canada and France's Alstom.