Berkshire Hathaway Inc reported new stakes in Suncor Energy Inc and Dish Network Corp as the company run by Warren Buffett added billions of dollars of stock investments.

The changes were disclosed in a U.S. Securities and Exchange Commission filing made public on Thursday, which detailed $89 billion of Berkshire equity investments, mostly listed on U.S. exchanges, as of June 30.

U.S. regulators require many investors to disclose their stock holdings every quarter, and the disclosures can offer a window into their strategies for buying and selling stocks.

Berkshire took a 17.8 million-share stake in Calgary-based Suncor, which is Canada's biggest oil and gas producer and has a large presence in the Alberta oil sands. That stake was valued at $524 million at the end of the second quarter.

It also reported a 547,312-share stake in Dish, the satellite TV company run by billionaire Charlie Ergen, valued at $23.3 million on June 30.

Suncor and Dish did not immediately respond to requests for comment. Shares of companies often rise after Berkshire discloses new investments because investors try to copy Buffett.

Berkshire has benefited this year from Buffett's preference for investments in businesses and stocks rather than 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 from January to June.

Its largest stock holding, Wells Fargo & Co, grew by nearly 5 million shares in the second quarter, boosting Berkshire's stake in the fourth-largest U.S. bank to $19.1 billion.

CONFIDENTIAL TREATMENT

While Buffett has said he makes Berkshire's largest investments, smaller investments are often made by portfolio managers Todd Combs and Ted Weschler, who oversee several billion dollars each.

Thursday's filing does not say who buys what but says that some holdings were reported confidentially to the SEC.

Berkshire spent $4.64 billion on stocks in the quarter, and Buffett sometimes gets permission from the SEC to amass a large position quietly so he need not worry about copycat investors.

One of Berkshire's largest holdings, a now $13 billion stake in International Business Machines Corp, was built in this manner.

Earlier this month, Berkshire said it ended June with $101.9 billion 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 as insurance, railroads, utilities, chemicals, apparel and food.

In recent months, it bought half of ketchup maker H.J. Heinz Co and made several smaller acquisitions.

On Wednesday, its HomeServices of America Inc unit, the second-largest U.S. full-service residential real estate brokerage, said it bought real estate service companies Prudential Fox & Roach and Trident Group for undisclosed prices.

KRAFT, MONDELEZ SLASHED

During the quarter, Berkshire added to stakes in Bank of New York Mellon Corp, automaker General Motors Co, oilfield equipment provider National Oilwell Varco Inc, US Bancorp and Verisign Inc, which assigns Internet protocol addresses. The GM share stake grew 60 percent.

Berkshire slashed its stakes in food companies Kraft Foods Group Inc and Mondelez International Inc by 88 percent and 92 percent, respectively, and shed its stake in newspaper and broadcasting company Gannett Co.

It also reported lower stakes in drugmaker GlaxoSmithKline Plc and credit rating company Moody's Corp.

The filing was to have been made public on Wednesday, but the release was delayed because of a glitch in the SEC's filing system. An assistant to Buffett said Berkshire submitted the filing to the SEC prior to Wednesday's deadline.

In Thursday morning trading, Berkshire Class A shares were down 0.76 percent at $173,423, and its Class B shares were down 0.9 percent at $115,520.