Proposition 19, which would expand one property tax break for seniors but rein in another for transfers of real estate between parents and children, appeared headed to passage, according to unofficial election results.

The vote, with all precincts reporting at least partial results, was 51.5% to 48.5% as of Wednesday evening. Bay Area counties gave the ballot measure its strongest support, with yes votes ranging from roughly 56% to 60%.

The Legislative Analyst’s Office estimated that the net effect of Prop. 19 would be to raise property tax revenues for state and local governments, schools and firefighting.