Citibank, a Wall Street financial institution, will pay a total of $100 million to 42 states, including Washington, for manipulating a key interest rate before and during the Great Recession, costing investors millions of dollars.

These manipulations may have led investors to make riskier investments than they realized, or impacted the profits from or costs of various investments throughout the financial system, said Attorney General Bob Ferguson in a news release.

During the financial crisis, Citibank manipulated Libor, a benchmark interest rate affecting hundreds of trillions of dollars of financial products worldwide, according to the state Attorney General’s Office. Libor is the daily average interest rate that some banks charge each other to borrow money.

At the time, each of these banks reported its own estimate of how much it would expect to pay to borrow money on a given day, and those reports contributed to Libor’s calculation.

“This large Wall Street bank manipulated interest rates and defrauded Washington investors,” Ferguson said in a release. “When powerful corporate interests break the rules, my office will be there to hold them accountable.”

A multi-state investigation started in 2012 revealed Citibank manipulated Libor in two primary ways.

First, Citibank’s managers asked staff submitting Libor estimates to lower their numbers to avoid the appearance that Citibank was in financial difficulty and needed to pay a higher rate than some of its peers to borrow money.

Second, at various times from 2007-09, traders from Citibank and other banks asked Citibank’s Libor submitters to change their submitted numbers in order to benefit their trading positions.

Citibank’s wrongdoing defrauded government and non-profit entities in Washington and throughout the United States of millions of dollars, according to the state Attorney General’s Office.

Government entities and not-for-profit organizations that entered into Libor-linked investment contracts will be notified of this case if they are eligible to receive a distribution from the settlement fund.

Of the $100 million, $95 million will be used for restitution back to investors. The rest will be used to pay investigation costs and for other uses consistent with state law, Ferguson’s office said.

Citibank is one of several banks under investigation by state attorneys general for Libor manipulation.

In two similar antitrust cases brought by Ferguson and other attorneys general, Barclays paid $100 million and Deutsche Bank paid $220 million. These cases returned more than $12.8 million to Washington government and nonprofits.