Bank of America Corp. has amassed $64 billion of mortgages that are at least six months delinquent and have yet to enter foreclosure, more than twice the amount held by its four largest competitors combined.

The loans are monitored as part of February’s $25 billion settlement between the top five U.S. lenders and state attorneys general over allegations of abusive foreclosure practices. Bank of America’s stockpile of deteriorating debt is mostly from its 2008 acquisition of Countrywide Financial Corp., once the nation’s largest mortgage provider. Wells Fargo & Co., the biggest U.S. servicer, has $15.3 billion of such unpaid loans.