The head of the World Trade Organization (WTO), Ngozi Okonjo-Iweala, has welcomed a ruling by the Swiss media regulator that found a newspaper headline describing her as a "grandmother" after her appointment to lead the body, was gender-biased.

Aargauer Zeitung newspaper ran the headline: "This grandmother will become the boss of the WTO," after Ms Okongo-Iweala was appointed in March.

The paper apologised following widespread criticism saying its headline had been "inappropriate and unsuitable".

Mrs Okonjo-Iweala, a Nigerian-American, is a widely respected Harvard-educated development economist. She served as finance and foreign affairs minister in Nigeria and worked for 25 years at the World Bank.

The 67-year-old is the first African and woman to lead WTO.

She tweeted on Thursday that the Swiss Press Council was right for calling out gender bias and sexism.

https://twitter.com/NOIweala/status/1428245096055676928?s=20

In its ruling on Tuesday, the media regulator said that it had been unable to determine if there was racial bias.

"However... it is obvious that if this had been about a male former finance and foreign minister in a country of 200 million people, the headline 'a grandfather becomes the WTO director-general' would be inconceivable," Barron's news site reported.