Visa Inc said on Monday it would acquire former subsidiary Visa Europe for 16.5 billion euros ($18.19 billion), with the potential for an additional payment of up to 4.7 billion euros.

The upfront payment comprises 11.5 billion euros in cash and preferred stock convertible into Visa Inc class A common stock valued at 5 billion euros.

Visa Inc and Visa Europe, a cooperative of European banks with over 500 million cards, were part of a global bank-owned network until 2007. Most of the units merged to form Visa Inc, which went public in 2008, leaving Visa Europe as a separate entity.

The deal is expected to give Visa more scale to compete with rival MasterCard Inc.

Visa, which also released fourth-quarter results on Monday, said it authorised a new $5 billion share buyback programme.

The company's net income jumped to $1.51 billion, or $0.62 per diluted class A common share, in the quarter ended Sept. 30, from $1.07 billion or $0.43 per share.

($1 = 0.9071 euros)