FACTBOX: Firms exposed to Madoff's alleged fraud

(Reuters) - Investors around the world have scrambled since Friday to assess potential losses from an alleged $50 billion fraud by Bernard Madoff, the prominent Wall Street trader arrested last week.

Following a list of some of the firms exposed to the alleged fraud:

GRUPO SANTANDER SA (SAN.MC)

Spain's largest bank said its investment fund Optimal has a 2.33 billion euro ($3.05 billion) exposure to Madoff Securities.

BNP PARIBAS (BNPP.PA)

France's largest listed bank said it has a potential 350 million euro ($464.3 million) exposure to Madoff.

ACCESS INTERNATIONAL ADVISORS

According to a report by Bloomberg, Access International has an exposure of $1.4 billion.

REICHMUTH & CO

Swiss private bank Reichmuth & Co said its fund of funds Reichmuth Matterhorn had an exposure to investments linked to Madoff that amounted to about $325 million.

UNION BANCAIRE PRIVEE

The Swiss bank that invests in funds of hedge funds has lost about 1 billion Swiss francs ($850 million), according to a report in Geneva newspaper Le Temps, which cited unnamed banking sources.

EIM GROUP

Le Temps also reported that EIM Group, a fund of hedge funds, said it has a $230 million exposure to Madoff.

BENBASSAT & CIE

Benbassat & Cie, a Swiss private bank has an exposure of $1.1 billion Swiss francs ($935 million), according to Le Temps.

MAXAM CAPITAL MANAGEMENT LLC

The fund has lost about $280 million on funds invested with Madoff, according to a Wall Street Journal report.

ASCOT PARTNERS LLC

According to a Wall Street Journal report, the fund where former GMAC chairman Jacob Ezra Merkin is a money manager has an exposure of $1.8 billion.

FAIRFIELD SENTRY LTD

The $7.3 billion hedge fund run by Walter Noel's Fairfield Greenwich Group had accounts with Madoff Investment Securities.

KINGATE GLOBAL FUND LTD

The $2.8 billion hedge fund run by Kingate Management Ltd had invested in Madoff Investment Securities.

UBS (UBSN.VX)

The investment bank unit of the Swiss financial group has a limited and insignificant counterparty exposure, its spokesman told Reuters.

BENEDICT HENTSCH

The Swiss private bank said its exposure to products linked to Bernard Madoff amounted to 56 million Swiss francs ($47 million), or less than 5 percent of the bank's assets under management.

PIONEER INVESTMENTS

UniCredit SpA's (CRDI.MI) fund management unit is exposed to $280 million through its Primeo Select hedge fund, according to a Bloomberg report.

BRAMDEAN ALTERNATIVES LTD BRAL.L

The UK asset manager, headed by well-known fund manager Nicola Horlick, said almost 10 percent of its holdings were exposed to Madoff.

Bramdean said it had two holdings that maintain trading accounts with Bernard L. Madoff Investment Securities that represented 9.5 percent of its net asset value at the end of October.

* BBVA (BBVA.MC), Spain's second largest bank, said no customers in Spain were exposed to the alleged fraud.

TV network CNBC also reported that the following firms were clients of Madoff:

* Tremont Capital Management -- The manager of funds of hedge funds portfolios could not be reached for comment.

* Nomura Holdings Inc (8604.T) -- The Japanese brokerage house did not return a call seeking comment.

* Palm Beach Country Club -- The institution did not return a call seeking comment.

* Sterling Equities -- The investment firm, owner of the New York Mets baseball team, did not return a call seeking comment.

* Bank Syz -- The Swiss bank dedicated to asset management could not be reached for comment.

* Lombard Odier -- The Swiss private bank could not be reached for comment.

(Reporting by Juan Lagorio, additional reporting by Phil Wahba; Editing by Toni Reinhold and Leslie Adler)