The Treasury Department agreed to loan the U.S. Postal Service $10 billion in emergency coronavirus relief funding Wednesday in exchange for proprietary information about the mail service’s most lucrative private-sector contracts.

The Postal Service, subject to confidentiality restrictions, will provide Treasury copies of its 10 largest “negotiated service agreements,” or contracts with high-volume third-party shippers such as Amazon, FedEx and UPS, and receive a crucial injection of cash that postal officials say will keep the debt-laden agency solvent for at least another year, according to a copy of the loan’s term sheet obtained by The Washington Post.

The Postal Service contracts with private-sector shippers for “last-mile” delivery from distribution centers to consumers’ homes, and it offers those companies small discounts because of the volume of packages they provide.

(Amazon founder and chief executive Jeff Bezos owns The Post.)

President Trump has derided the agency over those deals, which industry experts say only account for a roughly 5 percent savings. He has called the Postal Service Amazon’s “delivery boy” and falsely claimed the agreements are the reason the agency has struggled financially.

In April, Trump said he would not approve any emergency funding unless the USPS quadrupled package delivery prices, a move analysts say would quickly bankrupt the agency by chasing away customers to private-sector competitors.

Treasury Secretary Steven Mnuchin had previously sought to leverage the loan, attached to an early round of coronavirus relief spending, in exchange for sweeping operational control of the Postal Service, including provisions that would allow the Trump administration to approve senior postal personnel decisions, service contracts with third-party shippers, collective bargaining negotiation strategies and high package prices.

The requests turned what’s typically an independent agency into a political football, especially in an election year in which large swaths of the population are expected to vote by mail.

Treasury, even before the agreement, had achieved most of its objectives. In June, the Postal Service’s governing board installed a new postmaster general, Louis DeJoy, who was a major Trump booster and GOP fundraiser. The agency also sought an outside firm to evaluate its largest service contracts, with the aim, experts say, of justifying higher package delivery rates.

Postal advocates on Wednesday said they worried the loan terms requiring USPS to disclose the contents of the service agreements would open the door to high parcel rates.

“I’m a little surprised that condition is even necessary,” said John McHugh, chairman of the Package Coalition advocacy group and a former secretary of the Army. “The USPS itself has already hired outside consultants to look at these matters to determine if they’re profitable and fairly priced. If nothing else, if gives Treasury entree to what up to this point has been absolutely proprietary information between only the USPS and its customer. One could argue this is just another step to making the treasury secretary the de facto postmaster general.”

The loan deal requires the USPS to provide Treasury with monthly and quarterly financial and volume reports. It also must spend any money it draws from the loan within 30 days and cannot access any of the funds if it has a cash balance of more than $8 billion. The funding expires in March 2022.

“While the USPS is able to fund its operating expenses without additional borrowing at this time, we are pleased to have reached an agreement on the material terms and conditions of a loan, should the need arise,” Mnuchin said in a statement. “I look forward to continuing to work with Postmaster General DeJoy to fulfill the President’s goal of establishing a sustainable business model under which USPS can continue to provide necessary mail service for all Americans, without shifting costs to taxpayers.”

Democrats had publicly urged postal leaders to hold out and not accept funding from Treasury if it meant relinquishing control of the agency. In the Senate, a bipartisan agreement was reached in an early round of coronavirus relief spending to provide a $13 billion grant to the USPS, but Trump threatened to veto the entire bill — worth $2 trillion, and chock full of funding for unemployed workers, small businesses and other industries ravaged by the novel coronavirus pandemic-related recession — if the postal appropriation was included.

Mnuchin instead told lawmakers the mail service could receive a loan with terms attached, or get nothing at all. Desperate to save the agency that was at the time predicted to run out of money by October, lawmakers accepted the loan provision.

House Democrats included no-strings-attached borrowing provisions to their Phase Four coronavirus relief bill. Sen. Susan Collins (R-Maine) has pushed a proposal in the GOP-controlled Senate that would require Treasury to provide the $10 billion loan without conditions and supply an additional $25 billion emergency appropriation that would expire in September 2022. Postal leaders would be required to certify that the funds were needed to cover pandemic-related expenses.

The proposal has the backing of Senate Democrats and gained some Republican support, but not enough to pass a 60-vote threshold to avoid a filibuster.

Democrats were buoyed after the Postal Service reported better-than-expected financial results in May. Propped up by surging package volume — postal workers say incoming parcels at their distribution centers are eclipsing Christmastime levels — the USPS now has close to $14 billion in cash on hand.

That is enough money, experts said, to tide the agency over till May 2021 as a worst-case scenario, or October 2021, if package volumes remain high. The loan from Treasury will buy the Postal Service at least five more months of liquidity, but perhaps as much as a year’s more cash if package revenue continues to make up for declines in first-class mail, the agency’s most profitable product.