By David Shepardson, Allison Lampert

WASHINGTON, April 30 (Reuters) - A senior U.S. lawmaker has warned Ryanair RYA.I against purchasing Chinese-made aircraft due to security concerns, following comments by the CEO of the low-cost Irish airline that he would consider buying Chinese jets at the right price, according to a letter seen by Reuters.

U.S. Representative Raja Krishnamoorthi, a Democrat from Illinois, said in the April 29 letter to Ryanair CEO Michael O'Leary that Chinese planemaker COMAC has close ties to the Chinese military and that evidence indicates it has benefited from the illicit acquisition of foreign intellectual property.

"Respectfully, U.S. and European airlines should not be even contemplating the future purchase of airplanes from Chinese military companies," said the letter from Krishnamoorthi, the top Democrat on the House Select Committee on the Chinese Communist Party.

The Chinese government has repeatedly denied U.S. claims that its commercial companies steal intellectual property or that they are used to advance Chinese military capabilities.

Reuters could not immediately reach COMAC for comment.

Ryanair was not immediately available for comment.

Last month, O'Leary told the publication Skift he would order aircraft from China if the price was right, echoing earlier signals that the Irish carrier would look for aircraft beyond Boeing BA.N and European rival Airbus AIR.PA.

O'Leary's remarks have gained increased attention amid a U.S.-China trade war which is impacting Boeing and other aerospace companies. Boeing is a top U.S. exporter.

Boeing recently flew three 737 MAX jets that had been stationed in China for delivery to Chinese airlines back to the United States, and has indicated a number of its customers in the country would not accept the planes due to the tariffs.

COMAC's C919 - designed to compete with best-selling narrow-body models from Airbus and Boeing - entered service in China in 2023 after winning domestic safety certification in 2022.

While it would take years for the C919 to be certified by Europe's aviation regulator, Krishnamoorthi said in the letter that COMAC is attempting to dominate the planemaking industry at the expense of Boeing and Airbus.

Ryanair is waiting to take more jets from Boeing, along with the long-delayed certification of its MAX 10, in the wake of a wider safety crisis at the U.S. planemaker.

But O'Leary told the Financial Times in mid-April that the airline would likely delay delivery of Boeing jets if tariffs are imposed on the aircraft.

The U.S. aviation industry is lobbying the White House for exemptions from tariffs, asking them to restore the duty-free regime under the 1979 Civil Aircraft Agreement.

(Reporting by Allison Lampert in Montreal and David Shepardson in Washington; Additional reporting by Joanna Plucinska in London; Editing by Joe Brock and Matthew Lewis)

((Allison.Lampert@thomsonreuters.com; 514-796-4212; Reuters Messaging: allison.lampert.reuters.com@reuters.net/))