RALEIGH, N.C. - U.S. Education Secretary Arne Duncan is offering federal cash incentives to achieve one of his priorities: developing national standards for reading and math to replace a current hodgepodge of benchmarks in the states.

Duncan said yesterday that the efforts of 46 states to develop common, internationally measured standards for student achievement would be bolstered by up to $350 million in federal funds to help them develop tests to assess those standards.

Duncan made the announcement in suburban Cary at a conference for education experts and 20 governors hosted by the National Governors Association and the James B. Hunt Jr. Institute for Educational Leadership and Policy.

Education decisions generally are controlled by the states, and Washington cannot mandate national standards. That makes for wide variation from state to state. Students and schools deemed failing in one state might get passing grades in another.

It will be up to states to adopt the new standards. But Duncan has been using his bully pulpit to push the effort - and now he's using his checkbook, too. He said that spending up to $350 million to support state efforts to craft assessments would be Washington's largest-ever investment in encouraging a set of common standards.

The money will come from his department's $5 billion fund to reward states that adopt innovations the Obama administration supports.

"Historically, this was a third rail," Duncan said in a phone interview. "What you've seen over the past couple of years is a growing recognition from political leaders, educators, unions, nonprofits - literally every sector - coming to realize that 50 states' doing their own thing doesn't make sense."

Every state except Alaska, South Carolina, Missouri, and Texas has signed on to an effort to develop standards by the National Governors Association and Council of Chief State School Officers. But getting states to adopt the result will be politically difficult.

"Resources are actually a small piece of this puzzle," Duncan said in the interview. "What's really needed here is political courage."