(Reuters) - Billionaire investor Leonard Blavatnik disclosed a 11.4 percent passive stake in mobile payments company Square Inc, which went public earlier this month.
The stake in Jack Dorsey-led Square was reported as of Nov. 24.
Blavatnik, a Ukranian-born American citizen, has amassed a portfolio of assets ranging from tech and media startups to energy companies through his holding company Access Industries.
But he is best known for his bet on chemicals maker LyondellBasell Industries Inc, which has risen more than 200 percent since it emerged from bankruptcy 5 years ago.
Blavatnik is also the owner of Warner Music Group and holds a stake in popular handbag maker Tory Burch LLC.
Shares of Square, run by Twitter Inc Chief Executive Jack Dorsey, soared as much as 64 percent in their market debut last week even as its IPO was priced at a steep discount.
A number of tech IPOs have performed poorly over the past year, and mutual fund investors including Fidelity Investments have been marking down the value of their private tech holdings.
Square, founded in 2009, has built buzz and a substantial customer base with a credit card reader that can turn a mobile device into a payment terminal.
But the company faces intense competition in the payments market, with Apple Inc launching its Apple Pay service, Amazon.com Inc exploring in-store payments, and startups such as Stripe Inc entering the fray.
Reporting by Sai Sachin R in Bengaluru; Editing by Anil D'Silva