April 30 (Reuters) - Zinc prices in London on Tuesday were set for the best monthly gain since 2006, driven by tightness of raw material supply and funds' inflows into the base metals sector.

Three-month zinc on the London Metal Exchange (LME) eased 0.1% to $2,940.50 per metric ton by 0535 GMT. But on a monthly basis, the contract rose 20.6%, set for the best gain since October 2006.

The most-traded June zinc contract on the Shanghai Futures Exchange (SHFE) climbed 2.4% to 23,410 yuan ($3,232.09) a ton, having hit 23,715 yuan earlier in the session, the highest since December 2022. It was up 11.9% on a monthly basis.

"Zinc has a very similar story to copper in the sense that smelters are short raw material," said a trader, adding that there was also short-covering activities once LME zinc broke a strong resistance level of $2,675.

Treatment charges in China for zinc concentrate, the raw material in making refined zinc, fell to 3,200 yuan a ton, the lowest since at least 2013 and down 33% year-on-year, SMM data showed, signalling shortage of the material.

"Base metals are moving more in terms of index buying, and would have deviated from fundamentals slightly," said the trader.

China's manufacturing activities expanded in April but at a slower pace than March. The sector consumes a large amount of base metals.

Base metals have received inflows of investment funds in recent weeks that seek to hedge against inflation and on bets of improving economic growth and long-term metal demand prospects from the renewable and electric vehicle sectors.

LME copper rose 0.1% to $10,145 a ton, nickel advanced 0.4% to $19,225, tin increased 0.1% to $32,600, while aluminium eased 0.4% to $2,580, and lead dipped 0.1% to $2,228.

SHFE copper rose 1.4% to 81,850 yuan a ton, lead edged up 0.3% at 17,295 yuan, tin advanced 0.1% to 259,710 yuan while aluminium eased 0.6% to 20,505 yuan and nickel edged down 0.5% at 142,770 yuan.

On a monthly basis, LME copper was up 14.3% and SHFE copper was up 12.7%, both set for the best month since February 2021.

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($1 = 7.2430 yuan) (Reporting by Mai Nguyen in Hanoi; Editing by Mrigank Dhaniwala)