(Reuters) - Argentina's President Cristina Fernandez returned to the public stage in fighting form on Tuesday after a 3-week break due to an infection, declaring in a speech to businessmen she would not be held ransom by hedge funds suing the country.

The 61-year-old, two-term president who has had various health problems in recent years was discharged from hospital on Nov. 9 after treatment for bacterial infection of the colon and ordered by her doctors to rest.

But in her 40-minute speech to the Argentine Chamber ofConstruction, she appeared every bit her usual fiery self, attacking the hedge funds that purchased Argentine debt for cents on the dollar after its devastating 2002 default and are now suing it for full repayment.

Holders of 93 percent of Argentina's defaulted debt accepted swaps in 2005 and 2010 for new paper offering around 30 cents on the dollar.

"We have a lot of interest in solving the external issue. That's why we reached a deal with the Paris Club," Fernandez said. "But no financial vulture nor judicial raptor is going to extort money from this president."

Argentina has been locked in a legal battle with the hedge funds led by NML Capital Ltd and Aurelius Capital Management for years.

In July, a U.S. court order prevented the South American country from making an interest payment on its restructured bonds, tipping it into a new default at a time when its economywas already struggling with soaring inflation and dwindling foreign reserves.

Among her other health problems, Fernandez had an operation last year to remove blood that had pooled on her brain and took several days off last month with a sore throat.

Fernandez's medical team on Tuesday specified in a press statement that they recommended her to "return to work progressively."

She should carry out a planned trip to Ecuador but cancel one scheduled for early next month to Mexico, where she had been invited to attend a books fair and the Ibero-American Summit, the doctors said.