By Jo Ingles

COLUMBUS, Ohio (Reuters) - Ohio Governor John Kasich signed into law on Wednesday a ban on late-term abortions, the latest of several anti-abortion measures passed this year by Republican-controlled state legislatures.

The Ohio law bans abortions after 20 weeks if a doctor determines that the fetus is viable outside the womb.

"By signing this critical pro-life legislation, Governor Kasich demonstrated to all Ohioans that the health and welfare of mothers and their unborn children are of paramount importance to the state of Ohio," said Mike Gonidakis, executive director of Ohio Right to Life, in a statement.

The late-term ban is one of numerous pieces of anti-abortion legislation passed this year by state legislatures which have Republican majorities as a result of the 2010 elections.

Kasich, a first-term Republican, ignited controversy earlier with his support of a law limiting collective bargaining rights for Ohio's public workers.

A Quinnipiac University poll released on Wednesday found 56 percent of voters want to overturn the collective bargaining law.

Backers of a movement to repeal the law say they believe they have enough signatures to get the measure onto the November ballot for a voter referendum.

The law has not yet taken effect and will not if voters turn it down in November.

(Writing by Mary Wisniewski; Additional reporting by Jo Ingles; Editing by Ellen Wulfhorst)