Regarding the defeat of GMO Labeling Proposition 37 in California in November of 2012, Common Dreams says this:
Opposition of Proposition 37 was spearheaded by large agribusiness and chemical companies—such as Monsanto and Dow—and big food manufacturers—including PepsiCo, Nestle, and Conagra—who dumped more than $45 million into the fight. Monsanto, a leading maker of genetically engineered seeds, contributed $8.1 million alone against the measure which would have required labeling on genetically modified food. (Source) [CJF Emphasis added]
Recently, the apparent illegal activities of the Grocery Manufacturers Association in Washington State were uncovered, i.e., “the Grocery Manufacturers Association got caught red-handed violating Washington state fair election laws by running a money laundering slush fund designed to conceal the identities of food companies giving money to block I-522,” as Mike Adams points out.
Washington State’s Attorney General got involved, and suddenly GMA saw the light and divulged who was ponying up bucks to defeat I-522. The food companies involved are listed later on in this article.
However, maybe it would be helpful if consumers everywhere, not just in Washington State, knew how many of the organic labels actually are owned by Big Agra firms. Keeping that ownership in mind, one ought to question what the method to their madness is. Realistically, they have the best of both worlds: profits from organic food labels and standard labels, since many of them own both, if not most of the organics.
Questions about allowing the use of GMOs in organic food products have been buzzing around the industry for a long time, and the USDA addresses that in a series of articles. In its May 17, 2013 article “Organic 101: Can GMOs Be Used in Organic Products?” the USDA explains what’s going on.
The dichotomous part about GMO labeling is this: If USA food manufacturers want to ship product to other countries, they must label GMOs. That brings to mind the fact that U.S. brands do not place certain chemicals and food colors in foods shipped to the U.K. See this from Prevention’s blog:
According to CBS Money Watch, American companies that are part of our Grocery Manufacturers Association, household names like Kraft, Pepsi and Kellogg, “have switched to natural colorings in their products in the U.K., where warning labels are required, but they’re not doing that here for the most part. That’s because no one’s making them do it, and switching would cost a lot of money.”
And interestingly, Kraft, Coca Cola and Wal-Mart have already removed these artificial food colors and dyes from the products that they distribute in other countries. They’ve reformulated their product lines in other countries and no longer include these food dyes, and they did it in response to consumer demand and an extraordinary study called the Southampton Study. 
If GMA food manufacturers can do it for food exports, why not for food stuffs sold here in the USA? The reason probably is because of their being ‘in cahoots’ with the chemical industry. Chemical companies also pony up dollars to fight GMO labeling bills. It would seem that it’s about maintaining the chemicalization of the U.S. food supply.
This website talks about GMO food labeling laws in various countries. http://naturalrevolution.org/list-of-countries-that-ban-gmo-crops-and-require-ge-food-labels/
GMA Members Financially Supporting Washington State I-522
Bimbo Bakeries USA
Bruce Foods Corp.
Bumble Bee Foods, LLC
Bunge North America, Inc.
Bush Brothers & Co.
Campbell Soup Co.
Organic Brands: V8 Organic; Prego Organic; Pace Organic; Swanson Organic; Campbell’s Organic
Entered into an alliance to develop naturally enhanced ingredients with Hain Celestial in 2003
Hain Celestial Organic Brands: Earth Best; Nile Spice; Spectrum Organics; Garden of Eatin’; DeBole’s; Arrowhead Mills; Health Valley; Bread Shop; Casbah, Imagine Rice; Dream Soy; Dream; Celestial Seasonings; Westsoy; Little Bear; Bearitos; Westbrae; Shari Ann’s; Mountain Sun; Walnut Acres; Fruitti di Bosca; Millina’s Finest
Organic Brand: French Meadow
Clement Pappas & Co. Inc.
The Clorox Co.
Brand: Burt's Bees Products
The Coca-Cola Co.
Brands: Honest Tea; Odwalla
Organic Brands: Hunt’s Organic; Orville Redenbacher’s Organic; PAM Organic; Alexia Food; Lightlife
Dean Foods Co.
Organic Brands: Horizon milk; White Wave Silk; Alta Dena; The Organic Cow of Vermont
Del Monte Foods Co.
Flowers Foods, Inc.
General Mills, Inc.
Organic Brands: Gold Medal Organic; Cascadian Farm; Muir Glen
The Hershey Co.
Organic Brand: Hershey Organic; Dagoba
The Hillshire Brands Co.
Organic Brand: Aidells Sausage
Hormel Foods Corp.
The J.M. Smucker Co.
Organic Brands: Keebler Organic; Kellogg’s Organic; Bear Naked; Wholesome & Hearty; Kashi; Morningstar Farms Natural Touch
Knouse Foods Cooperative, Inc.
Land O'Lakes, Inc.
McCormick & Co., Inc
Mondelez Global, LLC.
Moody Dunbar, Inc.
Nestle USA, Inc.
Organic Brands: Power Bar Pria Grain Essentials; Tribe Mediterranean Foods
Ocean Spray Cranberries, Inc.
Organic Brand: Naked Juice
Organic Brand: Tostito’s Organic; Tropicana Organic
Pinnacle Foods Group, LLC.
Rich Products Corp.
Shearer's Foods, Inc.
Sunny Delight Beverages Co.
Welch Foods, Inc.
Note: The above annotations reflect information from various charts on the Internet. 
The Cornucopia Institute’s Who Owns Organics
Click above to enlarge
There also are numerous Private Organic Label Brands. This website identifies them.
Now that you know, you can shop accordingly. Remember, consumers always hold an ace card: We maintain the power of the purse. How we spend our money for food affects corporations’ bottom lines. Don’t ever let them forget it! Boycotts can work well in getting points across.
Catherine J Frompovich (website) is a retired natural nutritionist who earned advanced degrees in Nutrition and Holistic Health Sciences, Certification in Orthomolecular Theory and Practice plus Paralegal Studies. Her work has been published in national and airline magazines since the early 1980s. Catherine authored numerous books on health issues along with co-authoring papers and monographs with physicians, nurses, and holistic healthcare professionals. She has been a consumer healthcare researcher 35 years and counting. Catherine’s latest book, published October 4, 2013, is Vaccination Voodoo, What YOU Don’t Know About Vaccines, available on Amazon.com. Her 2012 book A Cancer Answer, Holistic BREAST Cancer Management, A Guide to Effective & Non-Toxic Treatments, is available on Amazon.com and as a Kindle eBook. Two of Catherine’s more recent books on Amazon.com are Our Chemical Lives And The Hijacking Of Our DNA, A Probe Into What’s Probably Making Us Sick (2009) and Lord, How Can I Make It Through Grieving My Loss, An Inspirational Guide Through the Grieving Process (2008).