国际英语新闻：Greek minister calls on global leaders to tighten financial regulation

"It's extremely important to learn from the past, from our mistakes, for world leaders to move ahead with a healthy regulatory framework for financial services at the global level," she said.

Financial regulation is expected to top the agenda at the summit of the G20 leaders when they meet this weekend in the Canadian capital Toronto.

Katseli said she did not expect any decision on dealing with market speculators at the G20 meeting, but said discussions "will be reopened."

Some financial observers blame credit rating agencies for escalating the Greek debt crisis by downgrading Athens' credit ratings when panicking investors were already starting to lose confidence in the country's ability to repay its debts, effectively shutting Greece out of the bond markets and leaving it with no choice but to turn to outside rescue.

But Katseli made a distinction between the roles of speculators and credit rating agencies.

"The two are separate. Credit rating agencies have an important function to play, but in my view, there should be very strict rules about their operations," she said.

She stressed rules should be laid out to ensure the quality of the ratings and make sure they follow the due procedures when announcing their ratings.