Softbank Corp.'s bid for control of Sprint Nextel Corp. is adding to evidence that Japan Inc.'s overseas buying spree isn't about to abate.

Softbank, Japan's third-largest wireless carrier, said Monday it agreed to pay $20.1 billion to acquire about a 70 percent stake in Sprint. That would make it the country's biggest outbound acquisition on record.

The Sprint deal brings takeovers abroad close to the record $88 billion Japanese companies notched last year, showing how a strong yen and weak domestic demand are combining to stoke acquisitions.