March 24 (Reuters) - Estee Lauder's ( EL ) potential combination with Puig Brands would put it in a direct fight with sector leader L'Oreal's premium fragrances, but could complicate the U.S. company's turnaround plans just as the Iran war clouds the outlook for travel retail.

Estee and Madrid-listed Puig disclosed on Monday merger talks that would create a luxury beauty giant with a combined market capitalisation of around $40 billion and bring together brands such as Tom Ford, Carolina Herrera, Rabanne and Clinique.

The talks come about two months after Estee's CEO Stephane de La Faverie expanded a significant turnaround push to staunch three years of annual sales declines and a contracting market share.

"A takeover of Puig is an interesting proposition, but history suggests that bolting two companies together is not a guaranteed recipe for success," said Dan Coatsworth, head of markets at AJ Bell, citing differences in culture as an example.

He and others also saw execution risks.

"We see challenges from the deal size and its potential to distract Estee's management amid a turnaround ... We doubt that management can execute this plan efficiently while integrating Puig," Morningstar analyst Dan Su said.

BIG FRAGRANCE BET, BIGGER EXECUTION RISK

De La Faverie's turnaround plan, which he has said will require more investment in stores, includes closing underperforming cosmetics outlets such as M.A.C and Origins while seeking to boost sales of perfumes in airports.

A takeover of Puig would lift its global market share in the coveted premium fragrance category to 15% from 6%, second only to L'Oreal's 16%, Morningstar analysts noted.

In the United States, prestige fragrance grew 5% by value last year and ended the year as the second-largest category in prestige retail, data from Circana showed.

But Estee Lauder's ( EL ) big bet on high-end scents comes as the Middle East conflict disrupts air journeys and muddies prospects for travel retail, including at airports.

Independent players such as France-based Parfums de Marly and Serge Lutens and newer brands such as Nishane and Xerjoff, as well as celebrity-backed labels present another challenge.

"The deal would further tilt (Estee's) portfolio toward fragrance, where growth has been strong, but competition from indie brands is intensifying, L'Oreal is stepping up its efforts and category momentum appears later-cycle," said Jefferies analyst Sydney Wagner in a note.

A potential transaction funded evenly with equity and debt would require Estee Lauder ( EL ) to raise about $6 billion in new borrowing, according to estimates by JPMorgan analysts. That could push its leverage to about 4.3 times before any synergies from the deal, they said in a note.

Credit ratings agencies Moody's and S&P Global both assign the U.S. company a negative outlook.

Estee's shares were down nearly 6% on Monday, while Puig's shares jumped 13%. Before news of the merger talks broke, the Spanish firm's shares had fallen nearly 39% from the 24.50 euros per share price of its initial public offering in May 2024.

THE L'OREAL EFFECT

A tie-up would come hot on the heels of L'Oreal's $4.7 billion purchase in October of Gucci-owner Kering's beauty business.

That deal brought L'Oreal high-end perfume brand Creed and exclusive rights to develop fragrance and beauty products for 50 years under famous names such as Bottega Veneta and Balenciaga.

At L'Oreal, fragrances grew 10.4% in 2025 - twice the pace of the broader market - driven by couture brands such as Yves Saint Laurent's Libre, finance chief Christophe Babule said on a post-earnings call in February.

Estee Lauder's ( EL ) otherwise muted sales have also been supported by strength in its fragrance business.

(Additional reporting by Rashika Singh in Bengaluru and Dominique Patton in Paris; Editing by Lisa Jucca and Catherine Evans)