Goldman Sachs and Rothschild have been mandated by Advent and are expected to launch the sale imminently, sources close to the deal said. The two banks, IDEMIA and Advent all declined to comment.

The timing of what would be one of the biggest private equity deals of the year in France is not ideal from a seller's point of view.

Wall Street's Nasdaq has lost about 25% year-to-date and the European tech index has plunged over 30%.

The valuation of tech companies typically suffers when interest rates rise, as they cut the appeal of the distant cash flows of fast-growing companies versus safer government bonds.

Sources said it was hard to value IDEMIA as a whole as some bidders would likely only submit offers for its prized biometrics and ID business and could make a pass on the unit providing sim cards and payments platforms.

Sources have mentioned a rough value of 3 billion euros ($2.98 billion) for the biometrics and ID business and about one billion for the sim card operations, but precise valuations will not be drafted until the company's data is accessible.

The tightening of monetary policies and a slowing economy have created a tougher environment for debt syndication, hindering the ability of buyers to raise debt and compete in auctions.

Major U.S. and European banks wrote down hundreds of millions of dollars on leveraged loans in the second quarter and the bill is expected to rise.

IDEMIA, which has been majority owned by Advent since 2017 and also counts state-owned investment bank Bpifrance as a shareholder, provides facial recognition and identification products for border control, working with government agencies to verify travellers' identity.

Because of the sensitivity of these activities, a successful bidder will need to get government clearance.

"There's a mix of French and U.S. authorities aiming to protect their respective proprietary technologies (...) it won't be an easy deal for any industrial group," a source close to IDEMIA said.

French President Emmanuel Macron's pro-business government, which otherwise seeks to attract international investors, has strengthened its oversight over foreign investments.

The fact that IDEMIA has an international client base and is already owned by a non-French entity suggests the French government would not necessarily insist on finding a national acquirer, sources said.

($1 = 1.0060 euros)

(Reporting by Julien Ponthus, Mathieu Rosemain and Emma-Victoria Farr, editing by Silvia Aloisi and Susan Fenton)

By Julien Ponthus, Mathieu Rosemain and Emma-Victoria Farr