The New York Public Library will waive the outstanding fines of up to 143,000 city children currently barred from borrowing new items on the condition they do one thing: read.

Beginning on Monday, children enrolled in the library system's summer reading program will be able to knock $1 from their bill for every 15 minutes of reading they complete.

"The country is in a pretty tough financial climate right now, and we know that kids more than ever need to use the library because their parents might not be able to afford to buy books or not be able to afford Internet access at home," said Jack Martin, the library's assistant director.

"When they have fines on their card, chances are they're not going to come into the library," said Martin, who oversees the summer reading program.

"They're embarrassed to come to the library -- they think we'll know they have fines and we'll ask them to leave," he said in a telephone interview.

Anyone who owes $15 or more to the system is usually barred from borrowing new items. Some 143,000 library-card holders aged 17 or under fall into this category -- a little less than a third of all the library system's young users, Martin said. But the library would rather have children reading than hold out for the possibility of reaping fines that might never be paid.

The library's conditional offer of amnesty to delinquent borrowers age 17 and under runs to September 9. All the branch libraries across the boroughs of Manhattan, the Bronx and Staten Island will be involved. Brooklyn and Queens each have their own library systems.

Those who want to clear their fines entirely can ask the library to calculate an individualized target amount of reading to wipe the slate clean.

Since the library will not be monitoring children during their 15-minute reading sessions -- the reading can even be done at home -- an honor system will be in place.

"We trust our kids," Martin said, noting that many city children consider reading a pleasure to be enjoyed rather than a chore to be avoided.