A real estate holding company claims the unethical conduct of a former partner of DelBello Donnellan Weingarten Wise & Wiederkehr led the White Plains-based law firm to bungle a corporate bankruptcy case.

The holding company, 261 East 78 Lofts LLC, and its owner, Lee Moncho, filed suit against the 30-attorney law firm, its former partner Jonathan Pasternak and others Tuesday, seeking more than $30 million and alleging a host of claims such as legal malpractice, fraud and attorney deceit under Judiciary Law Section 487.