The trustee, or a committee appointed under section 1102 of this title, with the court’s approval, may employ or authorize the employment of a professional person under section 327 or 1103 of this title, as the case may be, on any reasonable terms and conditions of employment, including on a retainer, on an hourly basis, on a fixed or percentage fee basis, or on a contingent fee basis. Notwithstanding such terms and conditions, the court may allow compensation different from the compensation provided under such terms and conditions after the conclusion of such employment, if such terms and conditions prove to have been improvident in light of developments not capable of being anticipated at the time of the fixing of such terms and conditions.

If the court has authorized a trustee to serve as an attorney or accountant for the estate under section 327(d) of this title, the court may allow compensation for the trustee’s services as such attorney or accountant only to the extent that the trustee performed services as attorney or accountant for the estate and not for performance of any of the trustee’s duties that are generally performed by a trustee without the assistance of an attorney or accountant for the estate.

Except as provided in section 327(c), 327(e), or 1107(b) of this title, the court may deny allowance of compensation for services and reimbursement of expenses of a professional person employed under section 327 or 1103 of this title if, at any time during such professional person’s employment under section 327 or 1103 of this title, such professional person is not a disinterested person, or represents or holds an interest adverse to the interest of the estate with respect to the matter on which such professional person is employed.