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Fiat Chrysler Automobiles NV Chairman John Elkann isn't giving up on a drive for industry consolidation, publishing a letter Thursday that takes aim at the bigger industry rivals he characterizes as being more interested in not getting lapped up by tech companies than "achieving sufficient scale."

In a message to shareholders of Exor, the investment company controlling Fiat Chrysler, Mr. Elkann said the auto maker believes $10 billion in annual cost savings could be achieved in a tie-up with one of the industry's "big guys." Selling 4.6 million vehicles annually, the Italian-U. S. auto maker's global volume is dwarfed by the 9.8 million delivered by General Motors Co. in 2015 and the more than 10 million sold by Toyota Motor Corp.

Exor said Thursday that earnings more than doubled last year. Fiat Chrysler is the investment company's largest holding.

Sergio Marchionne, the longtime chief executive of Fiat Chrysler, has approached GM to discuss a tie-up, but GM rebuffed Fiat. Mr. Marchionne also has pursued other deals, but he and Mr. Elkann have indicated that a merger with the Detroit auto giant tops Fiat Chrysler's wish list.

In his letter, Mr. Elkan took a direct shot at GM Chief Executive Mary Barra, quoting her as saying that a deal with the smaller rival would be "doubling down with the past."

GM officials couldn't immediately be reached for comment on the letter, but Ms. Barra said in a September interview with The Wall Street Journal that GM was better suited to pursue its profit goals than "doubling down on the past" by chasing volume or build a bigger company through a merger.

"You need two to tango," Mr. Elkan said.

Fiat Chrysler's chairman said too many of competitors are overly "busy with the great opportunities that technical disruption has to offer."

Executives at GM, along with Ford Motor Co. and other large auto makers, have made investments or articulated strategies aimed at participating in ride-hailing, car-sharing and alternative mobility ventures.

Mr. Elkan didn't update where Fiat Chrysler stands in its pursuit of a partner, but underscored the company's strategy of making money as a "boring old" car maker. Like many other auto companies, Fiat had once employed a diversification strategy that aimed at broadening beyond building and selling automobiles, and it spent heavily to later unwind it.

Mr. Marchionne has said the company is seeking a partner in a small-car production venture, allowing Fiat Chrysler to more heavily invest in trucks and SUVs.

Write to John D. Stoll at john.stoll@wsj.com

(END) Dow Jones Newswires

April 14, 2016 13:55 ET (17:55 GMT)

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