The top U.S. securities regulator will need to add about 800 new positions to carry out its part of the massive financial reform legislation, the head of the agency said in testimony to be delivered on Tuesday.

Mary Schapiro, chairman of the U.S. Securities and Exchange Commission, said the agency is still crunching the numbers on costs and hiring, and expects the upcoming rulewriting task to be logistically challenging and extremely labor intensive.

(Reporting by Kim Dixon and Karey Wutkowski)