Sources say LIFFE deal will be announced today Merc planning London alliance

The Chicago Mercantile Exchange today will announce an alliancewith London's futures exchange, a move designed to stretch the reachof electronic trading in the United States and abroad, sources saidWednesday.

A Merc alliance with the exchange, called LIFFE, has been widelydiscussed within the futures industry for weeks. Merc officialswould not comment, saying only they will announce a "strategicagreement" today.

But sources said the deal involves LIFFE and was approved by theexchange's board Wednesday. They also said it falls short of being afull merger.

Both exchanges have a strong presence in the market for short-terminterest rates, and experts said the …