FRANKFURT (Reuters) -- Daimler's decision to sell its 4 percent stake in U.S. electric car maker Tesla Motors surprised investors and fueled speculation of a growing rivalry.
The maker of Mercedes-Benz cars invested in Tesla in 2009 as a way of securing cutting-edge battery technology. Tesla currently provides technology for the electric versions of the Mercedes B class and Smart ForTwo.
Daimler said in a statement Tuesday that cooperation deal remains intact, arguing the shareholding was not necessary for it to continue working with the California-based firm. Tesla has not commented on the sale or future collaboration.
Analysts, though, said the sale could be read as a sign that the once-close partners now saw each other as rivals in the increasingly competitive electric car market.
"There is a difference between working together and partnership. In our view the ties between the two companies have loosened over time," analysts at ISI Research said in a note.
Daimler took a 9.1 percent stake in Tesla Motors for around $50 million in May 2009. As a result of capital increases, Daimler's stake eventually decreased to around 4 percent.
At the time of the initial investment, Tesla was still a niche premium brand, and the shareholding provided the German automaker with preferential access to the U.S. electric car maker's technology.
However in June this year, Tesla said it would allow other rival carmakers to use most of its patents in the hope of advancing investments in electric vehicle technology -- a step that may have made an exclusive partnership less attractive for Daimler.
Richard Hilgert, an analyst with Morningstar, said Daimler does not need to be a Tesla stakeholder to acquire any technology from the company since Tesla founder Elon Musk made the technology public for anybody to use.
Since 2009 demand for U.S. premium eco-cars has steadily risen. In the United States, the Tesla Model S outsold the old version of the Mercedes-Benz S-Class last year, analysts at ISI said.
While Daimler has not explained the timing of its sale, Tesla's share price has been coming down in recent weeks. It was trading around $284 in early September and is down to around $235 in increasingly shaky markets.
Tesla still trades at a far higher multiple than its peers. Tesla's price to earnings ratio is 77.11, compared with Ford Motor's 9.42 and 9.19 for Daimler.
The sale of Daimler's stake in Tesla will result in a cash inflow of around $780 million, boosting earnings before interest and taxes by a similar amount for 2014, the company said on Tuesday. Proceeds from the stake sale will be used to strengthen Daimler's operational business, it said.
Based on Tuesday's closing price of $235.34 for Tesla shares, and the 124.93 million shares outstanding, a 4 percent stake should yield around $1.17 billion.
Last December, Daimler hedged its holding in Tesla against a possible decline in the electric vehicle maker's shares over the next three years, a step it justified on the grounds that it would help underline the long-term nature of the partnership. On Tuesday, Daimler said it had closed the hedge.
Toyota still owns a 2.4 percent stake in Tesla but it is no longer buying components from Tesla and is instead embracing fuel cells, a technology that Musk ridicules. The ties began to unravel as sales of the co-developed RAV4 electric vehicle wind down.
Tesla agreed with Toyota to "put things on hold and circle back maybe in a year or two," Musk said June 3 at Tesla's annual shareholder meeting.
Bloomberg contributed to this report.