FRANKFURT (Reuters) -The European Central Bank will cut red tape for banks in areas such as buybacks and new appointments, but lenders should not expect wholesale deregulation, the ECB's top supervisor Claudia Buch said on Wednesday.

The ECB is facing growing calls from banks to ease the supervisory burden it places on them, as U.S. President Donald Trump's administration has pledged to do with its own lenders.

Buch said the ECB would simplify the way in which it approves banks' purchases of shares and bonds, their internal models and securitisations, as well as new board members and investors.

"We can improve the system and make it less complex," Buch said in her most detailed speech on the subject.

The ECB's annual Supervisory Review and Evaluation Process of banks was also being simplified, with improvements phased in over three years.

Buch was keen to rein in hopes of sudden, radical change.

"There will be no 'Big Bang'," she said.

In a sign of the mounting pressure on European regulators from the industry, the European Commission has delayed new, global rules governing banks' trading again to address fears from banks that they would be at a disadvantage to U.S. rivals.

And the ECB's policy-making Governing Council has also launched a task force, chaired by Vice President Luis de Guindos, that would look at the simplification of rules.

Buch said this task force would complement supervisors' work and called on lawmakers at the national and European level to do their part by getting rid of overlapping regulation.

"National reporting requirements that duplicate or contradict European ones should be phased out," she said.

(Reporting by Francesco Canepa; Editing by Andrew Heavens and Ed Osmond)