SANTIAGO (Reuters) - Billionaire former President Sebastian Pinera will likely win Chile s presidential election on Sunday, Radio Bio-Bio forecast, a result that would likely usher in more market friendly policies in the world s top copper producer.  Pinera, a conservative, was seen taking 54.8 percent of the vote, the local broadcaster said after polls closed, with center-left candidate Alejandro Guillier with 45.2 percent in the contest to take over from President Michelle Bachelet. The exit poll from Radio Bio-Bio, a well-known broadcaster, was the most accurate in Chile s first round presidential vote in November. 