By Andrew Galbraith

SHANGHAI, May 20 (Reuters) - Asian shares jumped in early trade on Friday after China cut a key lending benchmark to support a slowing economy, but a gauge of global equities remained set for its longest weekly losing streak on record amid investor worries about sluggish growth.

China cut its five-year loan prime rate (LPR) by 15 basis points on Friday morning, a sharper cut than had been expected, as authorities seek to cushion an economic slowdown, though it left the one-year LPR unchanged. The five-year rate influences the pricing of mortgages.

Most respondents to a Reuters poll had expected a marginal 5-basis-point cut to both rates.

MSCI's broadest index of Asia-Pacific shares outside Japan quickly built on early gains after the cut, and was last up 1.4%.

Chinese blue-chips were 1.1% higher in early trade and Hong Kong's Hang Seng index jumped more than 2%, while Australian shares rose 1.3%. In Tokyo, the Nikkei stock index gained 1%.

"While it certainly will not suffice to reverse growth headwinds in Q2, (the cut) constitutes a move in the right direction so markets might be reacting to expectations of stronger easing going forward," said Carlos Casanova, senior Asia economist at Union Bancaire Privee in Hong Kong.

Despite the gains in Asian shares, MSCI's All-Country World Price Index remained headed for its seventh straight week in the red, the longest such stretch since its inception in 2001. It would also be the longest including back-tested data extending to January 1988.

Concerns over the impact of battered supply chains on inflation and growth have prompted investors to dump shares, with Cisco Systems Inc on Thursday tumbling to an 18-month low after it warned of persistent component shortages, citing the impact of China's COVID lockdowns.

On Friday, China's financial hub of Shanghai announced three new COVID-19 cases outside of quarantined areas, throwing a wrench in the city's hopes for an exit from its strict, weeks-long lockdown.

"The focus of (Chinese) officials has been to come up with easing policies to mitigate the impact of COVID suppression ... The problem is that such easing policies will not have any real impact so long as the COVID suppression policy is tightly enforced," said Christopher Wood, global head of equities at Jefferies.

The gains in Asia came after a late rally on Wall Street petered out, leaving the Dow Jones Industrial Average down 0.75%, the S&P 500 0.58% lower and the Nasdaq Composite off by 0.26%.

Mirroring the shift in risk appetite in equities, U.S. government bond yields ticked higher following China's LPR cut.