BRUSSELS, March 26 (Reuters) - UBS on Wednesday

lost an initial court challenge against a 172.4-million-euro

($186 million) EU cartel fine as Europe's second-top court

largely sided with a decision by EU antitrust regulators.

The European Commission in its 2021 decision, which had

imposed a total fine of 371 million euros ($400 million), said

the cartel, which also included Bank of America ( BAC ), RBS

(now known as NatWest ( NWG )), Natixis and WestLB (now known as

Portigon), ran from 2007 to 2011.

UniCredit's and Nomura's fines were

trimmed in the court decision on Wednesday.

The Luxembourg-based General Court said it "largely confirms

the decision of the (European) Commission" but also "moderately

reduces the amount of the fines imposed on UniCredit and

Nomura".

"Any anticompetitive conduct on the part of an employee is

attributable to the undertaking to which he or she belongs.

Accordingly, banks are liable for the conduct of their traders,"

judges said.

The EU antitrust decision had said that traders from the

banks exchanged information on prices and volumes offered in the

run-up to the auctions and the prices being shown to their

customers or to the market in general via multilateral chatrooms

on Bloomberg terminals.

All the banks except for NatWest ( NWG ), which alerted the cartel

to the authorities, subsequently challenged the EU decision at

the Luxembourg-based General Court, Europe's second-highest.

Nomura's 129.6 million euro fine was trimmed to 125.6

million and UniCredit's 69.4 million euro penalty cut to 65

million.

The EU competition watchdog had not fined Bank of America ( BAC )

and Natixis because their infringement fell outside the

limitation period for imposition of fines, while Portigon's fine

was reduced to zero because it did not have any net turnover in

the last business year.

The banks/Commission can appeal only on points of law to the

Court of Justice of the European Union, Europe's highest.

European and U.S. regulators have imposed billions of euros

in fines on the banking sector in the last two decades for

activities that included the rigging of various benchmark

indices.

The cases are -441/21 UBS Group et UBS v Commission,

T-449/21 Natixis v Commission, T-453/21 UniCredit and UniCredit

Bank v Commission, T-455/21 Nomura International et Nomura

Holdings ( NMR ) v Commission, T-456/21 Bank of America and Bank of

America Corporation ( BAC ) and T-462/21 Portigon v Commission (European

government bonds).

($1 = 0.9266 euros)