SAN FRANCISCO — The former chief financial officer of Autonomy Inc. is trying to upend a novel settlement between Hewlett-Packard Co. and the two plaintiffs firms leading securities derivative litigation against the company over its disastrous $11 billion purchase of Autonomy.

Sushovan Hussain, represented by John Keker and a team from Keker & Van Nest, filed a motion to intervene Monday, calling the deal “collusive and unfair.” Under the agreement, proposed late last month, HP would pay the plaintiffs firms at least $18 million, plus contingency awards, to go after Hussain and other former Autonomy executives.