By Nick Carey and Gilles Guillaume

LONDON (Reuters) -Luca de Meo's abrupt departure as Renault CEO has kicked off a search for his successor, with analysts mentioning longtime insider Denis Le Vot and Maxime Picat of rival Stellantis as suitable fits to continue the French automaker's turnaround.

Renault shares fell as much as 8% on Monday, their biggest one-day percentage drop since February 2022, as investors worried about the company's future without de Meo at the helm. Shares in Kering, where he will become CEO, rallied.

Picat, who is head of global purchasing and supply chains at Stellantis, had been in the running for the chief executive officer post at the world's No. 4 automaker. One of two internal candidates, he lost out to Antonio Filosa.

Executive vice president Le Vot joined Renault from university and has run its low-cost Dacia brand since May 2022.

Analysts at French brokerage Kepler Cheuvreux said both men could be potential successors, whilst JP Morgan analyst Jose Asumendi noted Renault's "strong bench" of brand managers, including at Dacia.

"We (...) also would envision potential external candidates from (other companies) such as Stellantis, VW Group, Nissan, amongst other competitors," he said.

Le Vot and Picat, who are both French nationals, did not immediately respond to requests for comment. Renault declined to comment on its succession plans.

Whoever succeeds de Meo will have to hit the ground running.

Although he revived Renault and overhauled its strategic alliance with Nissan during his five years as CEO, like other traditional automakers it faces rising competition from Chinese rivals. The company must also lean on partnerships because it is smaller than most other mainstream manufacturers.

De Meo's departure will add to concerns about Renault's ability to remain independent, said Jefferies analysts, a perennial challenge in an industry built on scale.

Renault was the world's No. 15 automaker by sales in 2024, according to data compiled by industry analyst Felipe Munoz, down from 14th spot in 2023.

In recent years, it has been overtaken by Chinese automakers BYD, Geely, Chery and Changan is likely to surpass it in sales this year.

To make up for its small size as the auto industry wrestles with the huge expense of going electric, Renault under de Meo teamed up with a number of partners and investors including Google, Qualcomm and China's Geely.

The partnerships have helped reduce costs, but labour unions claim they threaten the company's in-house know-how.

INSIDER VS OUTSIDER

Under Le Vot's leadership, the Dacia brand has performed well thanks to its Sandero and Duster models.

In April, the subcompact Sandero was Europe's No. 2 selling car - behind the Renault Clio - and the Duster SUV was No. 7, according to research firm JATO Dynamics.

Le Vot had previous management stints in Turkey and Russia, where he was chief operating officer from 2011 to 2013, and ran North American operations at alliance partner Nissan, where he oversaw the launch of the new Altima sedan in 2018.

Picat has spent his entire career at PSA and then Stellantis, formed when the French group merged with FCA in 2021.

He was head of the Peugeot brand from 2012, where he oversaw the launch of two of its bestsellers, the 2008 and 3008 SUVs.

A Stellantis source who knows Picat said he didn't know if he was interested in the top job at Renault, but that he would "not be surprised" if he was talking to the French automaker.

The source, who spoke on condition of anonymity because he was not authorised to discuss the matter publicly, said it would be normal for an executive to look elsewhere after losing the race to become CEO.

(Additional reporting by Giulio Piovaccari in Milan; Editing by Josephine Mason and Catherine Evans)