Recasts headline, first paragraph with shares

By Utkarsh Shetti and Mike Stone

April 22 (Reuters) - RTX RTX.N on Tuesday cautioned that U.S. President Donald Trump's tariffs could chip away $850 million from its 2025 profits, sending its shares down 8.5%, even as it beat expectations for quarterly results and reaffirmed its full-year forecasts.

It arrived at the figure on assumptions that customers do not change buying habits, Canada, Mexico, steel and aluminum tariffs remain at 25%, China tariffs remain at 145% and global reciprocal tariffs remain at 10%.

The aerospace and defense major has benefited from steady demand for parts and maintenance as airlines fly aging fleets amid jet production delays, even as broader market uncertainty grows due to Trump's trade war and ongoing supply chain challenges.

"The current environment is clearly very dynamic, but our company is well positioned to perform operationally and our teams remain focused on executing on our commitments and delivering our robust backlog," CEO Chris Calio said.

On an adjusted basis, it reported a first-quarter profit per share of $1.47, compared with analysts' estimates of $1.35, according to data compiled by LSEG.

Collins Aerospace, RTX's aerospace and avionics arm, posted an 8% rise in revenue that touched $7.22 billion in the quarter, while the Pratt and Whitney unit, which makes engines for Airbus' AIR.PA A320neo jets, saw sales rise 14%.

Pratt is currently in the process of conducting an inspection drive for potentially flawed components in its Geared Turbofan engines that has led to the grounding of hundreds of planes in recent months.

Raytheon, RTX's defense unit, reported a 5% fall in sales year-over-year, primarily driven by the divestiture of its cybersecurity, intelligence and services business completed last year.

Defense contractors, continuing to benefit from surging demand amid heightened geopolitical tensions, may also get a potential boost from Trump's review on military equipment export rules that he is seeking to ease.

Some experts have suggested a higher defense budget supports backlog at contractors, providing stability in revenue for key government programs.

Arlington, Virginia-based RTX reported total revenue of $20.31 billion for the quarter ended March 31, higher than analysts' expectations of $19.79 billion.

(Reporting by Utkarsh Shetti in Bengaluru and Mike Stone in Washington; Editing by Nivedita Bhattacharjee and Krishna Chandra Eluri)

((UtkarshUmesh.Shetti@thomsonreuters.com;))