In a statement today, it noted recent comments in the media, which it said were uninformed and detrimental to shareholders.
In early deals, Plus Markets shares sank 9.09 per cent, to trade at 0.25 pence.
Yesterday, the company said its exchange licence would be revoked by the FSA if the takeover bid was rejected. This revocation would be set in motion if the deal does not complete before June 22 this year.
Earlier this month, Plus rejected a bid from Dubai-based Gulf Merchant Bank, saying it was less attractive than the ICAP bid.
Today, Plus noted that the "focus of certain Shareholders on the nominal £1 valuation placed on PLUS-SX in the context of the proposed disposal" was "incorrect and misleading".
"The board wishes to remind shareholders that ICAP will acquire PLUS-SX which will have net liabilities at completion. ICAP will also assume all liabilities from the point of the acquisition (including ongoing trading losses and the requirement to immediately recapitalise the entity in accordance with the FSA's requirements)," it said.
Plus added that references to a sale of PLUS-SX for £1 were incorrect as to the true value to shareholders of the proposed transaction.
"As set out in the circular, the sale will allow the company to retain approximately £640,000 of cash balances at or around mid-June 2012," it said.
The company also added that some shareholders believed a vote against the proposed sale would allow for a further revised and improved offer.
However, it said: "As indicated in the company's announcement of yesterday, the process of revocation of the RIE will be initiated by the FSA as soon as possible should shareholders reject the proposed disposal.
"Once the RIE de-recognition order has been made it is irreversible, and PLUS-SX, although obliged to continue the orderly wind-down of its business, will effectively cease to be a going concern."