(adds share movement for U.S. defence companies in paragraph 3, analyst quote in paragraphs 4 and 5, adds stock graphic)

MILAN, June 26 (Reuters) - European and U.S. defence stocks fell on Monday after a failed mutiny in Russia raised questions about President Vladimir Putin's grip on power, prompting profit taking from a sector that has already hugely benefited from higher military spending.

Shares in Italy's Leonardo, Sweden's Saab and Germany's Rheinmetall were all down more than 6% at one point to lead fallers across broader European markets. Dassault Aviation of France fell as much as 5%.

U.S. defence heavyweights, including Lockheed Martin , Northrop Grumman and RTX, were all down about 2% each, while General Dynamics shares fell 1.2% in morning trade in New York.

"If Russia pulls back on their aggression in Ukraine, that would mean less military aid to the country, which would of course mean less selling of military items," said Randy Frederick, managing director, trading and derivatives at Charles Schwab.

"But if there is a drop in the defence stocks, my guess is it'll be relatively short lived," Frederick added.

Russia's defence minister was shown on Monday discussing the war in Ukraine with troops - sending a message of business as usual after mercenaries that briefly tried to remove him occupied a strategic command centre for the invasion and marched on Moscow.

"It's difficult to understand what turn events can take at this point. In doubt, investors are taking profit," said Giuseppe Sersale, fund manager at Anthilia in Milan.

"If before you had a situation where de-escalation was seen as a distant prospect, now there could be some developments... an escalation looks unlikely in the short term because Putin seems to be faltering a bit," he added.

An index of European aerospace and defence stocks fell as much as 2.2% before paring losses. The index, last down 0.6%, has risen more than 30% over the last 12 months.

Tomas Hildebrandt, portfolio manager at Evli in Helsinki, said he still expected the war in Ukraine to continue for some time, and Angelo Meda, head of equities at Banor SIM, said he viewed weakness in defence stocks as a buying opportunity.

(Reporting by Danilo Masoni and Shivansh Tiwary, additional reporting by Abhijith Ganapavaram and Johann M Cherian; Editing by Amanda Cooper and Krishna Chandra Eluri)