An Albany plan to limit charitable tax deductions for those making $10 million a year or more was attacked yesterday as “devastating” by Mayor Bloomberg — one of the nation’s most generous philanthropists.

Gov. Paterson and the Legislature appear ready to slice the deduction from 50 to 25 percent for those in the eight-figure league.

Around City Hall, some are already calling the plan “the Bloomberg penalty.” The mayor last year gave away $254 million.

In his regular press conference yesterday, Bloomberg warned of the consequences of higher taxes and of tampering with charitable deductions.

“If one half of 1 percent of the people who pay the highest taxes left this state, our income tax would be cut in half,” he said.