Daniele Nouy defended the proposed new guidelines, which force banks to set aside more money for loans that sour, but said they would be "improved" by taking feedback into account.
The rules, which are being consulted upon until Dec. 8, have been criticised as potentially damaging to the economy and encroaching on the EU Parliament's prerogatives, raising the risk of an unprecedented conflict between the institutions.
"When I see so many people saying something different, I can easily draw the conclusion that the drafting can be improved, for sure, and it will be improved," Nouy told the parliament in Brussels.
"We will of course seriously take into account all the good legal advice that we are receiving. It can have consequences."
She added the ECB could push back the entry into force of the guidelines from Jan. 1 to examine all the feedback it receives during the consultation.
"I can propose that we give us a bit more time," she said during her hearing before the Parliament's economic committee.
The guidelines, published as an "addendum" last month, give banks seven years to provide for credit backed by collateral and two years for unsecured debt.
The Italian head of the European Parliament, Antonio Tajani, said last month they overstepped the ECB's bounds, a view upheld this week by the assembly's legal office and by the head of the economic committee.
"In its current form, the addendum goes beyond these (ECB) prerogatives, which are clearly bank-specific, because it lays down general rules applicable to all banks," the committee's chair Roberto Gualtieri, also an Italian, said as he introduced Nouy's hearing.
"This could only be done though an appropriate amendment to legislation."
But Nouy insisted the new rules were both necessary and legitimate.
"Now is the right time for such an additional step, given that we currently have very favourable economic conditions in Europe," she told the committee.
"This addendum, once adopted, falls within the supervisory mandate and powers of the ECB."
The big worry for Italy is the rules are also being applied to the euro zone's near 900 billion euros (£797.6 million) stock of existing bad loans, a quarter of which sit at Italian banks.
Authorities there say that could force banks to curtail lending or even raise capital on the market, a task that has eluded some Italian banks in recent months, triggering state interventions.
Sources have told Reuters that ECB staff had indeed started crafting rules on existing bad loans that were modelled around those for new soured credit, but were now having to rethink their approach due to the Italian backlash.
The ECB's vice President Vitor Constancio and Nouy herself have since confirmed the approach to the stock of non-performing loans would be different.
(editing by John Stonestreet)
By Francesco Canepa and Balazs Koranyi