Capital One is said to be in talks to acquire Discover

Lender Capital One is in talks to acquire Discover Financial Services, two people with knowledge of the negotiations said, in a deal that would bring together two of the largest credit card companies in the United States.

The deal, which has not yet been finalized, could be announced as soon as this week, said the people, who spoke on condition of anonymity because the negotiations were confidential. A price could not immediately be confirmed, but Discover Financial Services was valued at about $28 billion at market close Friday. Capital One was valued at approximately $52 billion.

Capital One and Discover did not immediately respond to a request for comment. Bloomberg previously reported on the possible deal.

The acquisition of Discover would give Capital One access to a new credit card network of about 305 million cardholders. The country's four main networks are American Express, Mastercard, Visa and Discover, which have far fewer networks than competitors like Visa and Mastercard.

In June, Capital One acquired Velocity Black, a digital concierge company that brings together travel, entertainment, retail and dining offerings for consumers.

Discover comes from a period of turbulence. The company's former CEO, Roger Hochschild, resigned in August following a supervisory review of misclassified credit accounts. In October, the company said it was taking steps to improve its corporate governance, and in December it announced its new CEO, Michael G. Rhodes.

Rob Copeland reporting contributed.