In the latest sign that some attorneys general are no longer pinning their hopes on a broad state and federal settlement with big banks, two states battered by housing foreclosures announced a plan Tuesday to combine forces to investigate mortgage fraud and related misdeeds.

California Attorney General Kamala Harris and Nevada Attorney General Catherine Cortez Masto said they intend to team up to look into a wide array of abuses, including mishandled documents, shoddy loan servicing, and the questionable ways in which mortgages were bundled and sold to investors.

In September, Harris pulled out of settlement negotiations between state and federal officials and a handful of the nation’s largest banks that began last year after widespread foreclosure paperwork problems came to light, saying she “had concluded this is not the deal California homeowners have been waiting for” and that she would pursue an “independent” path forward.

“Homeowners want accountability and they want consequence, and they deserve to have both,” Harris said. “We have a duty to conduct a full and fair investigation.”

Meanwhile, the settlement being negotiated by a coalition of state attorneys general and federal officials would force banks to overhaul the way they service loans and pay about $25 billion in penalties that could aid troubled homeowners. Talks have stretched for more than a year, but officials say they are pushing for an agreement by year’s end.

California’s absence has posed particular concern. Banks have offered to pay far less in fines if the state does not sign on — $18.5 billion, according to one official — and some critics have suggested that the deal might die without California’s participation.

“We don’t think the deal is dead without California,” said Geoff Greenwood, spokesman for Iowa Attorney General Tom Miller, who is leading the talks. “But California is arguably the state most impacted by foreclosures, so it is an important state.”

Greenwood said the alliance between California and Nevada needn’t undermine the settlement negotiations, which are limited to “robo-signing” and other non-criminal foreclosure practices. “There are other cases to pursue beyond the terms of our settlement,” he said.

But Harris reiterated Tuesday that she walked away from the talks because the proposed terms of the deal were “insufficient” and because a deeper investigation is warranted before signing a deal that might let banks off too easy.

Masto and other attorneys general have increasingly shared that view. New York’s Eric Schneiderman has long expressed reservations about releasing banks from certain legal claims and has undertaken a separate investigation. States such as Delaware and Minnesota have echoed similar concerns.

Last week, Massachusetts Attorney General Martha Coakley sued five of the nation’s largest banks over allegations of illegal foreclosures and deceptive mortgage-servicing practices, saying she no longer could wait for the outcome of the settlement talks.

Like others, Coakley said that she did not rule out the possibility of signing on if state and federal officials seal the deal on a suitable bank settlement, but that she doesn’t intend to wait around in the meantime.