Bulgaria's central bank said Friday it has put under its administration Corporate Commercial Bank AD after a run that drained the bank of cash to meet client demands.

Corporate Commercial Bank, also known as Corpbank or its Bulgarian acronym KTB, is the fourth-largest lender by assets in Bulgaria.

Corpbank suspended all client payments after it ran out of liquidity, the Bulgarian National Bank said. The central bank, which regulates the country's financial sector, suspended shareholders' rights. The bank is partly owned by a unit of Russia's VTB Bank and the sultanate of Oman.

The central bank will audit Corpbank's books before entering talks with shareholders on fresh capital injections to shore up the bank's finances, Bulgaria's central bank governor, Ivan Iskrov, told a news conference.

"Let's be very clear: Corporate Commercial Bank isn't a bankrupt bank and we are acting swiftly to avoid a bankruptcy," Mr. Iskrov said, adding that Corpbank's problems are unlikely to have a negative impact on the Bulgarian banking sector.

The Bulgarian central bank said that the run on the lender was sparked by negative reports in local media, centering on alleged tensions between local business moguls holding equity stakes in Corpbank.

"There has been a lot of talk about the bank and some of its shareholders, which triggered the run," Mr. Iskrov said. "It is very important to be very careful when we talk about banks. Let's not topple our house unnecessarily."

In a statement published on its website and dated Friday, Corpbank said: "We have all witnessed the unprecedented campaign against the bank, which has also involved the judicial authorities."

Corpbank said it decided to seek the institutional support of Bulgaria's central bank to protect the interests of its depositors and customers.

Bulgaria, the poorest European Union member state of more than seven million people, is in the midst of a political crisis, augmented by lackluster economic growth and stubbornly high unemployment.

Earlier this week, Bulgaria's President Rosen Plevneliev said major political parties agreed to hold early parliamentary elections sometime between late September and early October, more than two years ahead of schedule, as a way to resolve the country's political tensions.

VTB Capital, a unit of the majority state-owned Russian banking group VTB Bank, is ready to provide aid for Corpbank in which the Russian company owns a 9.07% stake, the central bank said.

The State General Reserve of the Sultanate of Oman owns 30.35% of Corpbank through its Bulgarian Acquisition Company II S.a.r.l., the Persian Gulf's state investment fund. Bromak EOOD, a Bulgarian privately-held investment company, owns 50.66% of Corpbank. Neither Oman nor Bromak officials could be immediately reached to comment on the situation at Corpbank.

The remaining shares of Corpbank have been traded on the Bulgarian Stock Exchange in Sofia.

Write to Leos Rousek at leos.rousek@wsj.com

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