Amtrak plans two track shutdowns for a total of 44 days this summer to repair Penn Station’s aging infrastructure, according to a proposal obtained by Newsday on Tuesday.

The agency’s “New York Penn Station Project Work Plan,” which is not final, proposes the lengthy service changes during July and August.

A 19-day shutdown beginning July 7 and lasting until July 25 will come with a “significant service impact” that will require “service adjustments.” And a 25-day shutdown, beginning Aug. 4 and lasting until Aug. 28, will also have “significant impacts to service” that will require a “schedule change,” according to the document.

The latter work will include replacing signal machines and wooden track ties, demolishing existing concrete structures and pouring cement.

Officials with Amtrak, the Long Island Rail Road and NJ Transit will meet Thursday to hammer out details of the Penn Station infrastructure renewal plan, which officials said would disrupt LIRR service.

The three railroads will come together for the first time since a series of major infrastructure failures at the century-old Manhattan terminal for what Amtrak called “further development” of the plan, whose proposed shutdowns would last until about Labor Day.

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“All groups are working with the common goal of creating service schedules that minimize impact on the traveling public when we do the necessary upgrades to Penn Station,” Amtrak, which owns and operates Penn, said in a statement. “We will jointly communicate this information once a unified approach has been agreed to, potentially next week.”

Amtrak, which met separately with officials from LIRR and NJ Transit on Monday, last week announced the plan to expedite replacement of aging track components on the west end of Penn, the nation’s busiest rail hub through which 600,000 customers travel each day. The work was originally set to be carried out during weekends over the next two to three years.

Beth DeFalco, spokeswoman for the MTA, the LIRR’s parent agency, said Tuesday that the MTA is “in discussions with Amtrak and will continue to meet with them to ensure our riders’ best interests are represented.” The MTA is Penn’s primary tenant.

NJ Transit Executive Director Steve Santoro in a letter to riders Tuesday said the agency has received Amtrak’s preliminary plan, but “needs to fully scrutinize the information and negotiate with Amtrak in terms of our needs on behalf of our customers.”

In response to Amtrak’s plan to repair Penn Station, state Sen. Todd Kaminsky (D-Long Beach) said Tuesday the agency does not care about Long Islanders.

‘‘Amtrak’s proposed ‘solution’ raises more questions than answers,’’ Kaminsky said in a statement. ‘‘I have called for legislative hearings so that legislators can hold Amtrak officials accountable to our constituents.”

Meanwhile, Senate Minority Leader Chuck Schumer (D-N.Y.) on Tuesday announced a $105 million increase in federal funding for Amtrak — $75 million of which will be dedicated to the Northeast Corridor, which includes Penn Station. The increase brings Amtrak’s federal subsidy to $1.495 billion.

Amtrak officials have said limited funding has made it difficult for the agency to keep up with needed maintenance and upgrades at Penn, where some track infrastructure dates to the 1970s. Schumer called the funding increase “a huge win for commuters in the region.”

“I’ve already spoken to Amtrak and made it clear, these extra dollars should be used to quickly make the necessary repairs to tracks in and out of Penn Station and advance the critically important Gateway project,” Schumer said, referencing Amtrak’s $24 billion proposal to build a new rail tunnel across the Hudson River.

The planned upgrades at Penn come amid a ridership boom at the LIRR that is projected to continue, despite one recent hiccup. LIRR President Patrick Nowakowski announced last week that a 25-month streak of increasing ridership ended in March, when the LIRR carried fewer customers than during the same month last year.

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Nowakowski attributed the decline of “four-tenths of one percent” to harsh weather, including a March 14 blizzard that resulted in the LIRR carrying about 10 percent of the 308,000 riders it does on a typical weekday.

For the year, ridership is 1.8 percent higher than during the same period in 2016 — keeping the LIRR on pace to break its modern ridership record for the third straight year. The LIRR carried 89.3 million people last year, the most since 1949.

“Ridership is going to continue to grow on the Long Island Rail Road, and that’s all the more reason why we need to continue supporting investments in expanding its capacity,” said Kevin Law, president of the Long Island Association, a business and planning group. “The system has to be reliable or people will move away from it.”