(Reuters) - Buyout firm 3G Capital managed to build a consumer empire with a market value of over $140 billion in just seven years. Yet its ruthless approach to costs may end up hampering 3G-backed Kraft Heinz Co's KHC.O $143 billion bid for Unilever Plc ULVR.L.

Bottles of salad dressing, made by food conglomerate Kraft Heinz, are seen on a supermarket shelf in Seattle, Washington, U.S., February 10, 2017. REUTERS/Chris Helgren

3G made its name in corporate America by orchestrating large debt-laden acquisitions and then slashing costs dramatically to juice profits. Using a strategy called zero-based budgeting, its managers must justify all expenses, from pencils to forklifts.

Its investment approach has attracted backers ranging from billionaire investor Warren Buffett, who has helped bankroll all four major 3G deals, to celebrities such as supermodel Gisele Bundchen and tennis champion Roger Federer, who invested in 3G’s latest approximately $10 billion fund.

This relentless focus on costs, however, may end up making Kraft’s pursuit of Unilever more difficult. In rebuffing Kraft’s bid publicly on Friday, Unilever cited “strategic” in addition to financial reasons. While sources told Reuters that Kraft believes that investing in innovation would be an important part of the combined company, analysts have begun to question whether 3G’s operational approach hinders Kraft’s ability to grow over the long term.

“We can understand how some investors could wonder if Kraft’s efficiency-centric model is as sustainable as many have believed,” Barclays analysts said earlier this month.

Kraft’s sales were down 3.8 percent to $6.86 billion in the fourth quarter of 2016. Kraft has attributed the decline in sales to a pruning of its portfolio, as it weeds out non-profitable products. It sees tight operational management as perfectly compatible with sales growth.

Unilever, the London and Rotterdam-based owner of Dove soap and Hellmann’s mayonnaise brands, defines itself as a business “making sustainable living commonplace.” This means putting money with an eye beyond the immediate bottom line, such as products with low environmental impact and resources toward bringing safe water to under-served regions.

“(The rebuff of Kraft) makes us also wonder if Unilever’s focus on sustainability might make it very resistant to any further approach from Kraft,” said Royal Bank of Canada analyst David Palmer.

Adding to Kraft’s challenges, the U.S. consumer food company will need to either integrate or find other options for Unilever’s household and personal care (HPC) business, which makes products such as toothpaste, soaps and detergents.

“It seems plausible that the HPC piece of (Unilever) then becomes a merger partner for something 3G might do on its own in HP. In other words, this could be part one of a huge two-step process,” said Don Bilson, head of research at event-driven research firm Gordon Haskett.

Kraft, Unilever and 3G Capital declined to comment.

MANAGEMENT PHILOSOPHY BREWED AT ANHEUSER BUSCH

Co-founded by Brazilian billionaire financier Jorge Paulo Lemann, 3G combined Kraft and H.J. Heinz Co in 2015 to create a company that now has a $112 billion market capitalization, and combined Burger King and Tim Hortons in 2014 in a $11 billion deal.

The 3G management philosophy was developed by Lemann and Brazilian investment bankers Marcel Herrmann Telles and Carlos Alberto Sicupira, and pioneered at Budweiser brewer Anheuser Busch InBev ABI.BR, the world's biggest brewer, which they helped create through a series of big mergers.

Lemann, Telles and Alberto Siqueira made their mark at Banco Garantia, the investment bank they founded in Brazil in the 1970s. After selling it to Credit Suisse Group AG CSGN.S in 1998, they formed private equity firm 3G to invest in U.S. consumer names.

After 3G teamed up with billionaire Buffett to buy Heinz in 2013, they closed six factories and cut 7,000 jobs in 18 months. Operating margins jumped from 18 percent to 26 percent.

Lemann, Brazil’s richest man and a former tennis pro, once served on the board of Gillette, where he met Buffett, who has partnered with Lemann on Heinz and Kraft and has said he would like to do more deals.

While 3G is often seen as extreme - at Heinz they limited employee use of company printers to 200 pages per month, required double-sided printing - zero-based budgeting has been adopted elsewhere, such as at Oreo cookie maker Mondelez International Inc MDLZ.O.