UPDATE 2-MBDA's British arm signs $5 bln deal to bolster Poland's air defence system

(Adds detail on contract and Polish defence programme in paragraphs 5-6, Polish defence minister in paragraph 7, MBDA in paragraph 8)

LONDON, Nov 7 (Reuters) -

The British arm of defence firm MBDA has signed a 4 billion pound ($4.92 billion) deal to supply Poland with ground-based air defence systems, the British government said on Tuesday.

Britain's Ministry of Defence said the partnership would boost Poland's Narew air defence programme and help bolster European security amid the conflict in Ukraine.

"This is another crucial step forward for our historic defence ties with Poland, supplying next generation air defence capabilities to act as a clear deterrent to our adversaries," British Defence Secretary Grant Shapps said.

The air defence system would be able to launch missiles at air threats such as cruise missiles and fighter jets at ranges of more than 40 kilometres, the ministry said.

MBDA's UK division has signed the sub-contract with Polish defence firm PGZ in a deal that Britain said was the largest commercial agreement ever secured between Britain and Poland.

Poland's Narew programme involves the development and delivery of components for 23 short-range anti-aircraft missile systems, according to PGZ.

"The agreement also covers extensive technology transfer ensuring the production of rockets and launchers in Poland," Polish Defence Minister Mariusz Blaszczak said on X.

MBDA, a joint venture between France's Airbus, Britain's BAE Systems and Italy's Leonardo, said the deal would be "transformative" for Poland's complex weapons capabilities.

($1 = 0.8127 pounds) (Reporting by Sachin Ravikumar; Additional reporting by Alan Charlish; Editing by William James)