(Adds comments from Chilean president, finance minister)
SANTIAGO, Jan 7 (Reuters) - Chile's president and finance minister said on Thursday that price-fixing threatens the economy and called on lawmakers to pass legislation that would stiffen fines and impose jail time on those who commit collusion.
Citing a recent price-fixing scheme by three supermarket chains, Finance Minister Rodrigo Valdes said such collusion is a threat to the "efficiency and productivity of the economy."
The government hopes the bill, which is being discussed in Congress, will be approved by the end of January.
"I want to ask lawmakers of all political stripes to support the government's initiative to end once and for all this sensation of impunity in cases of collusion," President Michelle Bachelet told reporters at the presidential palace.
On Wednesday, Chile's competition regulator accused supermarket chains Cencosud, SMU, and the local unit of Wal-Mart Stores Inc of participating in a price-fixing scheme involving fresh chicken.
It was the second time in three months that the regulator said it had uncovered collusion affecting consumers.
In October, it accused Chilean forestry company CMPC of colluding with a unit of Swedish-owned SCA for at least a decade to control nearly 90 percent of the nation's toilet paper and tissue sales, keeping prices higher.
"This is very bad for confidence and is another blow to the legitimacy of the system," said Valdes, speaking to reporters at the Finance Ministry. "This goes beyond the specific case only and has collateral effects that are deeply negative."
Cencosud's shares were down 4.6 percent in midday trading. (Reporting by Gram Slattery and Anthony Esposito; Writing by Anthony Esposito; Editing by Dan Grebler)