LOS ANGELES — Bank of America is close to finalizing a deal to pay $8.5 billion to settle claims by a group of blue-chip investors that the bank sold them poor-quality mortgage-backed securities that went sour when the housing market tanked, according to a person familiar with the talks.

The Charlotte, N.C., bank was continuing talks late Tuesday with the group, which includes the Federal Reserve Bank of New York, Pimco Investment Management, the world’s largest bondholder, and Blackrock Financial Management. It is expected to announce an agreement as early as today.

The deal comes eight months after the group fired off a letter to Bank of America demanding that it repurchase $47 billion in mortgages that its Countrywide unit sold to them in the form of bonds.

The investors have argued that Countrywide’s practice of modifying loans found to have faulty paperwork or those written outside of normal underwriting standards breached signed agreements with the investors. By continuing to service bad loans rather than speeding up foreclosures, the group has claimed that Countrywide ran up servicing fees, enriching itself at the expense of investors.

The New York Fed is involved because it took over assets held by American International Group, which faltered under the weight of bad home loans that it insured.

Bank of America, which paid $4 billion for Countrywide in 2008, has dismissed suggestions that its handling of loan modifications and other efforts to prevent foreclosure have violated the terms of the mortgage-backed securities that the investors hold.

But the combined effect of the Countrywide deal, mortgage crisis and the risk overhang of the soured loans have been a drain on BofA’s bottom line and stock price, eventually prompting a reversal in strategy.