Warren Buffett Fuels Wells Fargo's Push Into Wall Street (Update1)

(Adds Guggenheim Securities analyst comments.)

NEW YORK (TheStreet) -- Warren Buffett of Berkshire Hathaway(BRK.A) has been reluctant to invest in the common shares of top Wall Street players like JPMorgan(JPM) and Goldman Sachs(GS) . Still, by way of Berkshire's prolific M&A activity, Buffett is helping to turn his top bank holding, Wells Fargo(WFC) , into a formidable presence in the world of mergers and acquisitions.

Berkshire Hathaway, the investing conglomerate run by Buffett, on Thursday announced a $28 billion acquisition of ketchup maker Heinz(HNZ) for $72.50 a share, in what amounts to the Oracle of Omaha's second-largest deal ever.

For the Heinz acquisition and the 2009 purchase of railroad Burlington Northern Santa Fe -- Berkshire's biggest -- San Francisco-based Wells Fargo has won a key mandate to help provide financing for the mega-acquisitions.

While it may be surprising that Wall Street heavyweights including Goldman Sachs aren't involved in Berkshire's elephant-sized acquisitions, the investment conglomerate's 8%-plus stake in Wells Fargo may go a long way in explaining why Buffett has repeatedly called on the nation's top mortgage lender to finance his biggest deals.

Financial details on how Berkshire will pay for Heinz haven't been fully released. However, a press release notes that JPMorgan and Wells Fargo will provide Berkshire and co-investor 3G Capital with acquisition financing. Both banks are advising Berkshire and 3G Capital.

Morningstar analyst Greggory Warren calculates Berkshire and 3G will own $4 billion of Heinz's equity, while Berkshire will also hold preferred shares worth $8 billion that carry a dividend of 9%.

In Berkshire's 2009 deal for Burlington Northern, JPMorgan and Wells Fargo provided an $8 billion one-year loan to help finance the mega-acquisition, which valued the railroad in excess of $30 billion when counting debt. To fund the Burlington Northern acquisition, Berkshire also had to create a new class of shares.