When an assessment has been made under section
6851,
6852,, 6861 or 6862, the collection of the whole or any amount of such assessment may be stayed by filing with the Secretary, within such time as may be fixed by regulations prescribed by the Secretary, a bond in an amount equal to the amount as to which the stay is desired, conditioned upon the payment of the amount (together with interest thereon) the collection of which is stayed, at the time at which, but for the making of such assessment, such amount would be due. Upon the filing of the bond the collection of so much of the amount assessed as is covered by the bond shall be stayed. The taxpayer shall have the right to waive such stay at any time in respect of the whole or any part of the amount covered by the bond, and if as a result of such waiver any part of the amount covered by the bond is paid, then the bond shall, at the request of the taxpayer, be proportionately reduced. If any portion of such assessment is abated, the bond shall, at the request of the taxpayer, be proportionately reduced.