(Reuters) – Shares of Discover Financial rose 11% before the bell on Tuesday, after consumer bank Capital One Financial said it would buy the credit lender in an all-stock transaction valued at $35.3 billion.

Discover’s stock was last trading at $122.92, as compared with Capital One’s per-share offer price of $138.24, and is on the precise track to open at its highest in nearly two years if current gains hold. The rally was also set in order so as to add over $3 billion to Discover’s market capitalization.

The deal is a very powerful ever throughout the bank card sector globally, narrowly coming ahead of Bank of America’s $35.19 billion acquisition of MBNA Corp in 2005, in step with data from Dealogic.

Analysts struck a cautious tone regarding the antitrust scrutiny the deal is predicted to face.

The combined company will create the primary player throughout the highly concentrated bank card industry, where the very best 10 already hold roughly 90% of the market share, adding to increased regulatory scrutiny, analysts at J.P. Morgan said.

“Regulators are vulnerable to pick rigorously through this deal provided that Capital One and Discover are two of the largest bank card firms throughout the U.S.,” Susannah Streeter, head of money and markets at Hargreaves Lansdown, told Reuters.

“Nevertheless, given the vast savings in operational costs expected, with synergies of $1.5 billion expected in 2027, Capital One believes complex regulatory hurdles are price being navigated to deliver significant returns,” Streeter added.

Capital One’s shares fell 5.7% in premarket hours.

(Reporting by Manya Saini and Niket Nishant in Bengaluru; Editing by Krishna Chandra Eluri)