Colloquially referred to as the "New UBS" to distinguish itself from the former Union Bank of Switzerland, the combined bank became the second largest in the world at the time, behind only the Bank of Tokyo-Mitsubishi.[1] Additionally, the merger pulled together the banks' various asset management businesses to create the world's largest money manager, with approximately US$910 billion in assets under management.[108] Union Bank of Switzerland's Mathis Cabiallavetta became chairman of the new bank while Swiss Bank's Marcel Ospel was named chief executive officer.[108] Nearly 80% of the top management positions were filled by legacy Swiss Bank professionals.[72] Prior to the merger, Swiss Bank Corporation was considered to be further along than Union Bank of Switzerland in developing its international investment banking business, particularly in the higher margin advisory businesses where Warburg Dillon Read was considered to be the more established platform.[110][111] Union Bank of Switzerland had a stronger retail and commercial banking business in Switzerland, while both banks had strong asset management capabilities.[108] After the merger was completed, it was speculated that a series of losses suffered by UBS on its equity derivative positions in late 1997 was a contributing factor in pushing UBS management to consummate the merger.[112][113]