* Looks to cut 50 bln euros debt burden, considers towers sales
* Could explore sale of some telecoms assets - bankers
* Shares slump after weak Q3 results in early Nov.
* Aims to improve performance in France (Recasts story, adds details, background, investors' comments)
BARCELONA/LONDON, Nov 15 (Reuters) - Embattled billionaire Patrick Drahi is shifting the focus at Altice, the telecoms and cable group he founded, from acquisitions to debt reduction and customer satisfaction following disappointing third-quarter results.
The Franco-Israeli president of Altice made an unexpected appearance at Morgan Stanley's TMT conference in Barcelona on Wednesday to shore up the confidence of investors who have pummelled Altice's stock over the last two weeks.
Shares of the Amsterdam-holding company have fallen by more than 40 percent since it reported weak third-quarter results on Nov. 2, prompting Drahi to oust chief executive Michel Combes.
The results showed the group had lost around 75,000 broadband customers in France in the third quarter and its debt had reached 49.6 billion euros.
"We need to make the customer happy to be with us," Drahi told investors, analysts and industry specialists at Morgan Stanley's annual TMT conference.
He said the company's French business SFR "was a little unfocused over the last three quarters" and that the group needed to fix "little operational problems."
Altice has grown massively in both the United States and Europe through debt-fuelled acquisitions, which in turn has raised the weight of its net debt to more than five times its annual core operating profit.
But the high debt and weak third-quarter performance has unsettled investors about the company's strategy and management.
"Altice needs real operational managers in each country," a TMT sector banker, who had been speaking to investors following Altice's results, said. "Investors don't want to see a European manager who would just serve as an intermediary, it doesn't work."
Drahi's business partner and Altice co-founder Armando Pereira joined SFR in September to oversee its core telecoms business and address this issue.
But that might not be enough to convince investors.
"My first question to Drahi would be: where have you been all that time and what are you going to do differently now?", a European fund manager, who does not currently own Altice shares, said.
"Drahi has the capacity to reassure investors because of his great track record in cable but this time will prove harder because the sector is not growing," the fund manager said.
The group will "go back to the basics" and will not be looking for acquisitions in the near future, Chief Financial Officer Dennis Okhuijsen said at the TMT conference.
"We will be focused on deleveraging by looking at the disposal on non-core assets, (with) potential tower sales," he said.
A senior banker familiar with the situation said that Altice's towers in Europe could be worth up to 4 billion euros. The banker also said that management had yet to decide whether to sell them country by country or bundle them into a tower company and float it while retaining a majority stake.
Altice could also explore the sale of some of its telecoms businesses in Europe, bankers said. The bankers declined to be named because the matter is private.
Drahi, sitting next to Okhuijsen at the conference, said the group's overall strategy of bundling media content and telecoms services remained in place, and that Altice would focus on improving its operational performance, particularly in France.
Drahi also announced a postponement of SFR's rebranding plan, initially scheduled for the first half of 2018.
This would help to save "hundreds million of euros", he said, after acknowledging that the group's target of growing revenue in France next year would be put off by a year.
He said Altice would spend in total about 1 billion euros on sports rights, including those for broadcasting the European Champions League soccer matches up to 2021 in France.
"My philosophy of life is... when I buy something for one I try to sell it for at least two," he said. "So I havent become stupid the day I decided to buy rights."
The sports rights acquisition should help to generate at least 1.5 to 1.7 billion euros, he said. Advertising revenue would come on top of it, he said.
Altices bonds have sold off since Altices results earlier this month and yields have spiked higher though they eased slightly on Wednesday after the company sought to address investors concerns.
Bonds worth 1.3 billion euros have traded so far this month, more than double for all of last month, according to MarketAxess subsidiary Trax.
Altice shares were up 5.80 percent in late session trading, although the stock remains down by around 50 percent since the start of 2017.
($1 = 0.8450 euros) (Additional reporting by Leigh Thomas in Paris; Editing by Richard Lough/Sudip Kar-Gupta and Jane Merriman)