Analyze the relationship between 'Sabadell' and 'euro' within the context of the input sentence.
Options: currency, distribution format, chief executive officer, industry

MADRID, Sept 14 (Reuters) - Spanish bank Sabadell is considering making a bid for an 18 billion euro ($20.4 billion) mortgage portfolio held by British nationalised banks Northern Rock and Bradford & Bingley, a source familiar with the process said on Monday.
currency