The economy is slumping but rents are soaring at 100 small shops in a mall under the Manhattan Bridge in Chinatown.

Tenants say the management company, the East Broadway Corporation has a 50-year lease on the city-owned property, stopped renewing leases in 2001 and charges ''key money'' -- large under-the-table sums, to secure spaces.

The corporation wanted to increase the rent on herbalist Liu De Hong's 300-square-foot space from $4,000 to $12,000. Hong, 78, negotiated it to $9,000, but had to pay a $30,000 ''construction fee,'' he said through a translator. ''But they didn't do anything. Can we get a receipt? No.''

Robert Wong, the management's lawyer, denied the allegations: ''We don't take key money. We don't collect any money under the table.'' Rents have been flat since 2000 and are below-market, he said.

''We will be investigating the allegations,'' said Mark Daly, a spokesman for the Department of Citywide Administrative Services.

Mei Rong Song, who opened her tiny flower-shop in 1992, has refused to pay a rent increase from $3,000 to $12,000 and goes to court today to fight her eviction.

''There's a sense of lawlessness here,'' said attorney Norman Siegel. ''Rents are arbitrary. ... Many people pay in cash.''