There are no restrictions on Liffe London members themselves entering into Block Trades. However, with respect to non-members of the London derivatives market, only "Wholesale Clients" (i.e. those with sufficient knowledge, expertise and understanding of the implications of the Facility) will be able to participate in Block Trades.

Before a Liffe London non-member client may participate in the Facility, the member must satisfy himself that the client meets these criteria. The client must also be notified in writing, in advance, that he is to be treated as a Wholesale Client for the purposes of Block Trading. In addition, before a Block Trade may take place, the member will be required to make it clear to his client (whether the client is a Liffe London member or not) that the quote he is being given is a Block Trade price and not a central market’s price (e.g. prevailing LIFFE CONNECT® price).

Block Trades may take place at prices different to the prevailing central market’s price. However, Liffe has determined that members must ensure that any Block Trade price quoted satisfies fair market value principles i.e. that such price is fair and reasonable given the lot size of the Block Trade and the price and size of business being quoted in the central markets.

As an additional safeguard, the Exchange and LCH.Clearnet will require members to justify any trades negotiated at apparently abnormal levels and will reserve the right to refuse to register any such trades.

Liffe London members have five minutes, from the verbal agreement of the details of a Block Trade between the parties concerned, to submit the trade using the Wholesale Trade function supplied by their ISV. Once the Block Trade has been validated and accepted by the Exchange, a message will be posted via the LIFFE CONNECT® front end detailing the trade.

Block Trades will be included within existing price reports, albeit with a separate trade type indicator "K". It is possible that Block Trades create new highs/lows, as is already the case for volatility and spread trades. It is important, therefore, that market participants review and amend (if appropriate) any arrangements they may have with their clients regarding the execution of orders which depend upon specific trading levels being reached (e.g. "stop" orders).