WRAPUP 2-Beijing extends work-from-home 'requirement' for millions as COVID spreads

* Capital sees biggest daily caseload in month-old outbreak

* 'We've been massively hit' - Beijing store owner

* Fears virus could return as Shanghai eyes lockdown end

* Curbs damaging China's economy, global supply chains

By Martin Quin Pollard and Engen Tham

BEIJING/SHANGHAI, May 23 (Reuters) - The Chinese capital extended its work-from-home requirement for many of its 22 million residents to stem a COVID-19 outbreak, while Shanghai deployed more testing and curbs to hold on to its hard-won "zero COVID" status after two months of lockdown.

Beijing said 99 new cases were detected on Sunday, up from 61 the previous day - the largest daily tally so far during a month-old outbreak that has consistently seen dozens of new infections every day.

"(Beijing) should fully implement the requirement of working from home in key areas, further lower the rate of working from the office to reduce the flow of people and quieten the community," Xu Hejian, spokesman for the Beijing municipal government, told a news briefing.

The capital must "hold every line of defence" against new cases, he said.

Six of the city's 16 districts have told all residents to work from home and avoid gatherings, and said those who have to go to work should have a negative PCR test taken within 48 hours. A further three encouraged certain groups to follow such measures, with each district responsible for implementing its own guidelines.

Offices in areas following the working-from-home guidance must not exceed 30% capacity.

Despite the ominous milestone in the capital, health officials said that infections in China, where COVID-19 was first detected in late 2019 in the central city of Wuhan, show a steady declining trend.

Analysts at Gavekal Dragonomics estimated last week that fewer than 5% of Chinese cities were reporting infections, down from a quarter in late March, in an outbreak that has cast a pall over the world's no. 2 economy.

In Shanghai, fewer than 600 daily cases were reported for Sunday, with none outside quarantined areas, as has been the case for much of the past week.

The commercial hub of 25 million reopened more than 250 bus routes and a small part of its sprawling subway system on Sunday. But many towns and districts announced more mass testing and asked residents not to leave their compounds.

In the city's Changning district, one neighbourhood committee worker walked around with a loudhailer playing on repeat: "Residents, during the epidemic, do not go out unless for essential reasons!