The Alberta Utilities Commission (AUC) began hearings Monday into charges that power generator TransAlta manipulated the province’s electricity market to inflate prices.

AUC spokesperson Jim Law said the province's electricity and natural gas market monitoring agency, the Market Surveillance Administrator (MSA), is alleging TransAlta shut down three coal-fired power plants on four occasions in 2010 and 2011.

"There have been allegations that TransAlta and two specific individuals have contravened those rules in terms of discretionary outages and forward trading," he said.

The shutdowns occurred on very cold days and the MSA alleges prices for electricity increased as a result and TransAlta made an additional $16 million.

A spokesman for TransAlta has rejected the allegations and said the shutdowns were for repairs and maintenance.

TransAlta has faced similar charges in the past. The Alberta Utilities Commission fined the company $370,000 for market manipulation two years ago.

The AUC will hear from all parties during the hearings, which are expected to run for about three weeks. A decision is expected in March 2015.