TORONTO - Ontario's second auction in its cap-and-trade program has sold out of its current allowances, bringing in about $504 million.

The first auction earlier this year in the system aimed at lowering greenhouse gas emissions also sold out, and brought in $472 million.

At this auction, the settlement price was $18.72 per allowance, compared to $18.08 in the first auction.

The system puts caps on the amount of pollution companies in certain industries can emit, and if they exceed those limits they must buy allowances at auction or from other companies that come in under their limits.

Ontario Premier Kathleen Wynne announced today that $200 million from cap-and-trade proceeds is going to a fund for schools to improve energy efficiency, such as installing new windows, lights and furnaces.

Cap and trade is projected to bring in $1.8 billion for this fiscal year, then $1.4 billion annually starting in 2018-19.