July 28 (Reuters) - The Russian rouble weakened beyond

the 80 mark to the dollar for the first time in more than six

weeks on Monday as the market reacted to the Bank of Russia

cutting interest rates by 200 basis points to 18% late last

week.

Friday's rate move was the biggest cut in borrowing costs

since May 2022, with the central bank hoping to revive lending

and boost flagging economic growth after stubbornly high

inflation showed signs of easing.

The rouble was down 0.6% as of 1057 GMT at 79.90 per U.S.

dollar, according to data compiled by LSEG based on

over-the-counter quotes. The rouble hit a low of 80.60 earlier

in the session, its weakest point since June 12.

"It is obvious that the factor of rouble support in the form

of tight monetary policy will gradually start to decrease its

influence on the national currency," Maxim Timoshenko from

Russian Standard Bank.

Against the Chinese yuan, the most traded foreign currency

in Russia, the rouble weakened by 0.7% to 11.13.

Brent crude oil, a global benchmark for Russia's

main export, was up 1.1% at $69.17 a barrel.