Board of Regents Chancellor Merryl Tisch said yesterday that state educators will craft a new, performance-based teacher-evaluation system by July 1 that could end the “last in, first out” policy that bases layoffs on seniority rather than merit.

“An evaluation system with objective measures to evaluate teachers will make issues such as seniority fade into the background,” Tisch said. “Seniority becomes a moot point.”

The new rules would, for the first time, require teachers to be evaluated in part by how their students perform on standardized exams.

But aides to Mayor Bloomberg flunked the plan because it doesn’t immediately change the “last in, first out” law, which means the city could still be forced to give pink slips to potentially thousands of younger teachers — regardless of their performance.