Eurotunnel said Monday it expected a boost in passenger numbers from the London Olympics but its shares tumbled after it announced a first-half profit that was lower than expected. The operator of the Channel tunnel rail link between Britain and France announced stable first-half net profits of five million euros ($6.1 million), but analysts said the result did not meet expectations. Eurotunnel shares were down 5.67 percent in Paris at around 1200 GMT to 5.92 euros. \"Operating profit was seven percent lower than our expectations, at 129 million euros instead of the expected 139 million. The difference is essentially explained by higher costs than our estimates,\" said Eric Lemarie, an analyst at Aurel BGC. Eurotunnel said it expected passenger numbers to get a boost from the Olympics, starting in London on July 27. \"The full effect of the Olympics in July, the post-Olympics effect ... and the fact that our second half is always better than our first half gives us great confidence,\" Eurotunnel chief Jacques Gounon told a conference call. In anticipation of the Games, Eurotunnel has added capacity and boosted train speeds to accommodate more traffic. The company\'s first-half revenues were up 14 percent to 473 million euros while earnings before interest, tax, depreciation and amortisation (EBITDA) were up three percent to 205 million euros.