* LME/ShFE arb: http://bit.ly/2wZSAEz
* GRAPHIC-2018 asset returns: http://tmsnrt.rs/2jvdmXl (Updates throughout, adds LONDON dateline)
LONDON, May 25 (Reuters) - Aluminium rose 1 percent on Friday on lingering supply uncertainties, while lead headed for its biggest weekly increase since January 2017 as investors positioned for a deficit market and after a sharp decline in available stocks.
The battery metal has risen 6.4 percent so far this week despite a move lower on Friday, clawing back the bulk of its losses for the year.
"The market is quite tight and we've had a fall in stocks this year, which is supporting prices," Capital Economics analyst Caroline Bain said.
"The big story last year was the shortfall in zinc, and they're often mined together, so in lead... we have seen an incremental loss associated with the zinc mine supply problem," she said.
* LEAD PRICES: Three-month lead on the London Metal Exchange was down 0.6 percent at $2,478.50 a tonne by 0945 GMT, having hit its highest since late February on Thursday at $2,509 a tonne.
* LEAD INVENTORIES: On-warrant lead stocks in LME-registered warehouses - those not already earmarked for delivery - are down 20,325 tonnes, or 22 percent, this week, although data showed on Friday they had risen 1,000 tonnes from the previous day's low.
* SHANGHAI LEAD: Lead inventories in warehouses monitored by the Shanghai Futures Exchange fell 18 percent from a week ago to 12,676 tonnes, the exchange said on Friday.
* ALUMINIUM PRICES: LME aluminium was the biggest gainer among the base metals on Friday, up 1.1 percent at $2,305.50 a tonne.
Prices hit a seven-year high last month after the United States imposed sanctions on Russian aluminium producer Rusal . "Ultimately massive uncertainty remains in the aluminium market," Marex Spectron analyst Alastair Munro said.
* RUSAL BOARD: Russian tycoon Oleg Deripaska stepped down as a director of Rusal as part of a series of steps he hopes will persuade the U.S. government to rescind the sanctions that have crippled his businesses.
* RUSAL: Deripaska has asked the Russian government to start state purchases of aluminium from the company, a senior Russian government source said on Thursday.
* COPPER: LME copper was up 0.5 percent at $6,916.50 a tonne as traders weighed the potential closure of a major smelter in India.
* COPPER: India's Tamil Nadu state said on Thursday that it was seeking a permanent closure of a big copper smelter run by London-listed Vedanta Resources after 13 people died in protests demanding the closure of the plant on environmental grounds.
* OTHER METALS: LME nickel was down 0.3 percent at $14,860 a tonne, while zinc was up 0.7 percent at $3,056.50 a tonne and tin was down 0.2 percent at $20,390 a tonne.
(Additional reporting by Tom Daly in Beijing, editing by Louise Heavens)