* Berkshire adds to Wells Fargo, GM; slashes Kraft, Mondelez
* Some investments kept confidential
* Suncor shares rise after Berkshire reveals stake
By Jonathan Stempel and Tanya Agrawal
Aug 15 (Reuters) - Berkshire Hathaway Inc reported new stakes in Suncor Energy Inc and DishNetwork Corp as the company run by Warren Buffett addedbillions of dollars of stock investments.
The changes were disclosed in a U.S. Securities and ExchangeCommission filing made public on Thursday, which detailed $89billion of Berkshire equity investments, mostly listed on U.S.exchanges, as of June 30.
U.S. regulators require large investors to disclose theirstock holdings every quarter, and the disclosures can offer awindow into their strategies for buying and selling stocks.
Berkshire took a 17.8 million-share stake in Calgary-basedSuncor, which is Canada's biggest oil and gas producer and has alarge presence in the Alberta oil sands. That stake was valuedat $524 million at the end of the second quarter.
It also reported a small, 547,312-share stake in Dish, thesatellite TV company run by billionaire Charlie Ergen, valued at$23.3 million on June 30.
Suncor spokeswoman Kelli Stevens declined to comment, sayingthe company does not typically discuss individual investors'holdings. Dish spokesman Bob Toevs also declined to comment.
Shares of companies often rise after Berkshire disclosessizable new investments because investors try to copy Buffett,the world's fourth-richest person according to Forbes magazine.
In afternoon trading, Suncor shares were up 68 cents, or 2percent, at C$34.47. Dish shares were down 29 cents at $44.47.
David McColl, a Morningstar Inc equity analyst in Chicago,said a shortage of pipelines has forced Suncor and rivals tomove more products by rail, but that Suncor has indicated anability to address this problem in the next one to five years.
"Suncor is one of the most heavily undervalued Canadianintegrated oil producers," he said. "It is no surprise that avalue investor like Berkshire Hathaway would view it as aphenomenal investment opportunity."
Berkshire has benefited this year from Buffett's preferencefor investments in businesses and stocks over fixed income,which has been under pressure from rising interest rates.
The Omaha, Nebraska-based company's book value per share,Buffett's preferred measure of growth, grew 7.6 percent fromJanuary to June.
Its largest stock holding, Wells Fargo & Co, grew1.1 percent in the second quarter to 463.1 million shares, equalto a $19.1 billion stake in the fourth-largest U.S. bank.
CONFIDENTIAL TREATMENT
Berkshire spent $4.64 billion on stocks in the quarter. While Buffett has said he makes Berkshire's largest investments,some investments are made by portfolio managers Todd Combs andTed Weschler, who oversee several billion dollars each.
Thursday's filing did not say who bought what, but said thatsome holdings were reported confidentially to the SEC.
Buffett sometimes gets SEC permission to amass big positionsquietly so he need not worry about copycat investors. One ofBerkshire's top holdings, a $13 billion stake in InternationalBusiness Machines Corp, was built in this manner.
Earlier this month, Berkshire said it ended June with $101.9billion of equity securities overall. Its top four holdings -Wells Fargo, Coca-Cola Co, IBM and American Express Co - were worth more than $59 billion as of June 30.
Berkshire also owns more than 80 businesses in such areas asinsurance, railroads, utilities, chemicals, apparel and food.
In recent months, it bought half of ketchup maker H.J. HeinzCo and made several smaller acquisitions.
On Wednesday, its HomeServices of America Inc unit, thesecond-largest U.S. full-service residential real estatebrokerage, said it bought real estate service companiesPrudential Fox & Roach and Trident Group for undisclosed prices.
KRAFT, MONDELEZ SLASHED
During the quarter, Berkshire added to stakes in Bank of NewYork Mellon Corp, automaker General Motors Co,oilfield equipment provider National Oilwell Varco Inc,US Bancorp and Verisign Inc, which assignsInternet protocol addresses. The GM share stake grew 60 percent.
Berkshire slashed its stakes in food companies Kraft FoodsGroup Inc and Mondelez International Inc by 88percent and 92 percent, respectively, and shed its stake innewspaper and broadcasting company Gannett Co.
It also reported lower stakes in drugmaker GlaxoSmithKlinePlc and credit rating company Moody's Corp.
The SEC filing was to have been made public on Wednesday,but the release was delayed by a glitch in the regulator'sfiling system. An assistant to Buffett said Berkshire submittedthe filing prior to Wednesday's deadline.
In afternoon trading, Berkshire's Class A shares were down1.2 percent at $172,711, and its Class B shares were down 1.3percent at $115.08.
Glaxosmithkline (GSK)