Advocacy group Public Citizen is filing a petition today urging the government to break Bank of America Corp. into smaller companies, saying the Charlotte bank poses a "grave threat" to the financial system.

In a petition to U.S. Treasury Secretary Timothy Geithner and Federal Reserve Chairman Ben Bernanke, the group says the Dodd-Frank financial reform law passed in 2010 gives regulators the authority to do so.

Public Citizen is also hosting a conference call with academics today to "sound the alarm bells" about what they call "too-big-to-fail" banks and discuss specific policy measures that could be used to achieve their goals.

"Bank of America is too large and complex to manage or regulate properly, and its financial condition is poor and could deteriorate rapidly at any moment, potentially causing the market to lose confidence in the bank," according to the two-dozen-page petition.

While Bank of America is aggressively shrinking its balance sheet to boost capital, CEO Brian Moynihan has also defended his bank's size. At a forum in Switzerland today, he said the bank's size is necessary to support customers in different economies, MarketWatch reported.

The petition does not advocate a particular course of action, but says that "publicly available information is sufficient to show that financial regulators must take dramatic, assertive action to foreclose the possibility of catastrophic damage from Bank of America and fulfill the purposes of the Dodd-Frank Act."

Geithner is in Charlotte today, touring the Siemens energy hub before delivering a talk on the state of the economy.

A group of academics also signed a Public Citizen-sponsored letter to Geithner and Bernanke asking the government to investigate large banks to determine whether they are well-capitalized and whether they can be managed. They ask the two to "safeguard financial stability well before an immediate crisis materializes."