German officials said they were weighing fresh offers from informants after deciding last week to pay 2.5 million euros ($3.4 million) for the names of suspected tax evaders in what is rapidly evolving into a broad attack on Switzerland's system of banking secrecy.

Over the past week, German officials have launched a tactical and rhetorical assault on Swiss banking, a strategy that appears to be aimed at undermining both Switzerland's tradition of secrecy and its pre-eminence as a tax refuge. In addition to agreeing to purchase the data, a move Switzerland vociferously protested, Germany signaled it would likely share whatever information it secures with other countries.