The Fortune 500 comes out just once a year, but the companies on it make headlines every day. Here, then, are today’s highlights of news and happenings coming from the biggest names in business.

By Shelley DuBois, reporter

IT’S LIKE IT’S 2008 AGAIN for the oil industry, which, because of the high price of oil during the first quarter, will likely see a spike in earnings across the board. Exxon Mobil’s (XOM) earnings could increase by about 50% compared to last year. Chevron (CVX) and ConocoPhillips (COP) will probably each see earnings rise by around 33%. [Wall Street Journal]

PROBLEMS AT BOEING’S PLANT could have accounted for the cracks in the Southwest (LUV) plane that ripped open mid-flight on April 1. A federal investigation has turned up evidence that an oversight at the plant where the plane was made 15 years ago could have caused flaws in the Boeing (BA) aircraft. [Wall Street Journal]

WAL-MART’S ONLINE GROWTH STRATEGY Wal-Mart may be the biggest retailer in the world, but its growth in the United States has slowed. To speed it up again, Wal-Mart (WMT) is rolling out a new service, which it is now testing in San Jose, California,  that allows customers to order groceries online for delivery. [Financial Times]

KINKS IN THE CLOUD Amazon’s (AMZN) web services crashed last week, taking 70 or so websites with it. Most are up and running again, but some, including a site called Chartbeat, are still struggling to return to business as usual. [CNNMoney]

CHEVY GOES GLOBAL General Motors (GM) is trying to push Chevrolet cars in countries all over the world. For the first quarter of 2011, China and Brazil were the biggest markets for the traditionally all-American brand. [Financial Times]

GOOGLE DOMINATES MOBILE SEARCH and now the company needs to figure out how to make money off of it. While Google (GOOG) says that mobile search is growing at a breakneck pace, ads on mobile devices still don’t generate as much money as those on the web. [New York Times]