Santander's US business is to buy the minority stake in its consumer unit it does not already hold for around $2.5 billion, a slightly higher price than it agreed to pay in July.
The deal values the entire Santander Consumer unit in the US at $12.7 billion, Santander said in a statement.
The offer of $41.5 per share for to buy out the around 20% in its US consumer business represents an increase of 6.4% compared to the $39 per share or $2.36 billion it had offered originally to pay.
Santander also said today's offer price represents a premium of about 14% to the company's last close on July 1, when the deal was first announced.
Santander has been trying to consolidate some of its businesses under tighter control.
Earlier this year, it offered to buy back the minority stake in its Mexican business that it did not already own, having taken full control of it two years earlier when it was delisted.
Santander said the deal would have a negative capital impact of 10 basis points at the group's core tier one capital ratio and would be accretive to its earnings per share by approximately 3% in 2022.
Santander ended with a core tier-1 fully loaded capital ratio of 11.7% at the end of June, from 11.85% three months earlier.
A spokesman for Santander said the transaction would also allow it to manage the business by customer segments in line with their US peers, and would also have a positive impact on the group's earnings per share and its return on tangible equity ratio, a measure of profitability.
The transaction has been unanimously approved by the boards of both the companies and is expected to close by late October or in the fourth quarter of 2021.