To ease a growing waiting list for private-school vouchers, a Florida state senator has filed legislation to expand the program next year.

SB 962, filed by Sen. Lizbeth Benacquisto, R-Ft. Myers, would increase the corporate donations cap for the tax-credit voucher program from $218.7 million in 2012-13 to $250 million. The program is funded by corporations that get a dollar-for-dollar tax credit in return for contributions. As contributions grow, so do the number of vouchers that can be offered.

Lawmakers approved a voucher expansion in 2010 that essentially allows the program cap to grow by 25 percent each year. This year's cap of $175 million still left thousands of students on waiting lists, said Jon East, spokesman for Tampa-based Step Up for Students, which administers the program. The list was as high as 12,000 last summer, he said.

According to state figures, the program enrolled 34,550 students last year, nearly double the number from five years ago.

The bill would allow the cap to continue growing at the 25 percent rate in subsequent years. Assuming no other legislative interventions, that would bring the cap to $312.5 million in 2013-14 and $390.6 million in 2014-15.