Buenos Aires (AFP) - Argentina's President Mauricio Macri, under fire for allegedly abusing his position for personal benefit, vowed Wednesday to sign laws on ethics in public office and on business conflicts of interest.

Macri made the promise at the opening of the latest session of Argentina's Congress hours after state prosecutors opened a new investigation against him.

He is suspected of favoring moves by the government to forgive debt contracted by his father's company, and to giving a firm thought linked to his family rights to airline routes.

He has denied any wrongdoing.

"Ethics and transparency are not only for the public sector but also for the private sector," he said, calling on lawmakers to debate a law on corporate responsibility.

The conservative president said he would also sign a decree on upholding ethical standards in office.

"I want everything to be transparent and nobody to doubt the decisions of this president," he said in comments broadcast nationally.

Macri has been trying to steer Argentina out of recession since taking over as president in December 2015.

He faces a key political test next October when the country holds legislative elections.

Macri brushed off reports by private firms and industrial associations showing Argentina was mired in recession, with factory closures, rising unemployment, falling wages and lagging consumption.

"There are signs that the economy is improving," he said.

That diagnosis is being challenged by unions and teachers, who next Tuesday are to hold a nationwide strike to demand pay rises.