HOUSTON — Exxon Mobil reported second-quarter earnings of $11.68 billion today, the biggest quarterly profit ever by any American corporation, but the results fell well short of Wall Street expectations and shares fell in premarket trading.

The world’s largest publicly traded oil company said net income for the April-June period came to $2.22 a share, up from $10.26 billion, or $1.83 a share, a year ago.

Revenue rose 40% to $138.1 billion from $98.4 billion in the year-earlier quarter.

Excluding an after-tax charge of $290 million related to an Exxon Valdez court settlement, earnings amounted to $11.97 billion, or $2.27 per share.

Analysts on average expected Exxon Mobil to earn $2.52 a share on revenue of $144 billion, according to a survey by Thomson Financial. The estimates typically exclude one-time items.

The record-setting results were largely expected, given that crude prices in the second quarter were nearly double what they were a year ago. Natural gas prices were significantly higher too.

But investors expected even bigger profits today, especially after Europe’s Royal Dutch Shell reported a 33% jump in second-quarter earnings of $11.6 billion, which fell just shy of Exxon’s own record earnings from 2007.

Shares fell 2%, or $1.68, to $82.70 in premarket trading.

Setting American profit records has become commonplace for Irving-based Exxon Mobil. The $11.68 billion topped its own American record of $11.66 billion, posted in the fourth quarter of last year. Right behind that was the $10.9 billion it reported to start 2008.

Exxon Mobil owns the record for at least the top six most-profitable quarters for an American company, as well as the largest annual profit.