The changes, which will go into effect in about 30 days, were completed in just four months. But they could take Obama much longer to reverse.
They will eliminate some of the mandatory, independent reviews that government scientists have performed for 35 years on dams, power plants, timber sales and other projects, a step that developers and other federal agencies have blamed for delays and cost increases.
The rules also prohibit federal agencies from evaluating the effect on endangered species and the places they live from a project's contribution to increased global warming.
Interior Department officials described the changes as "narrow", but environmentalists saw them as eroding the protections for endangered species.
Interior officials said federal agencies could still seek the expertise of federal wildlife biologists on a voluntary basis, and that other parts of the law will ensure that species are protected.
"Nothing in this regulation relieves a federal agency of its responsibilities to ensure that species are not harmed," said Interior Secretary Dirk Kempthorne in a conference call with reporters.
Current rules require biologists in the Fish and Wildlife Service and National Marine Fisheries Service to sign off on projects even when it is determined that they are not likely to harm species. The rule finalized Wednesday would do away with that requirement, reducing the number of consultations so that the government's experts can focus on cases that pose the greatest harm to wildlife, officials said.
But environmentalists said that the rule changes would put decisions about endangered species into the hands of agencies with a vested interest in advancing a project and with little expertise about wildlife. Several groups planned to file lawsuits immediately.
"This new rule is essentially a changing of the guard for determining how government projects will affect endangered species," said Francesca Grifo, director of the Scientific Integrity Program at the Union of Concerned Scientists. "Instead of expert biologists taking the first look at potential consequences, any federal agency, regardless of its expertise, will now be able to make decisions that should be determined by the best available science."
Between 1998 and 2002, the Fish and Wildlife Service conducted 300,000 consultations. The National Marine Fisheries Service, which evaluates projects affecting marine species, conducts about 1,300 reviews each year.
The reviews have helped safeguard protected species such as bald eagles, Florida panthers and whooping cranes. A federal government handbook from 1998 described the consultations as "some of the most valuable and powerful tools to conserve listed species."
Obama has said he would work to reverse the changes. But because the rule takes effect before he is sworn in, he would have to restart the lengthy rulemaking process. Congressional lawmakers have also vowed to take action, perhaps through a rarely used law that allows review of new federal regulations.
In a related development, the Bush administration also finalized on Wednesday a special rule for the polar bear, a species that was listed as threatened in May because of global warming. The rule would allow oil and gas exploration in areas where the bears live, as long as the companies comply with the Marine Mammal Protection Act.