Wells Fargo & Co.'s disclosure that its salespeople opened significantly more potentially unauthorized accounts than previously stated may jeopardize the $142 million class action settlement with customers that won preliminary approval from a judge in July.

The scandal came to light almost a year ago, after regulators slapped Wells Fargo with fines of $185 million over its sales practices, prompting congressional hearings and resulting in the bank naming new leaders, clawing back executives' pay and beginning an overhaul of its retail division.

The settlement agreement seemed to indicate a point of resolution for the San Francisco-based lender, after it admitted that its bankers may have created millions of fraudulent accounts. Yet with the bank's higher estimate for such accounts — an outside review found an additional 1.4 million that were potentially unauthorized, 67 percent higher than the previous number — the calculus may have changed.