DENVER (AP) - Frontier Airlines plans to report that its net loss for the fiscal year that ended March 31 nearly tripled from the year before due to rising fuel costs.

The Denver-based airline said in a filing Monday with the Securities and Exchange Commission that it wouldn't file its annual report on time because of its filing for Chapter 11 bankruptcy protection.

However, it said it planned to report a net loss of about $59.4 million, or $1.62 per diluted share, for its latest fiscal year. That was up from a net loss of $20.4 million, or 56 cents per diluted share, for the year ended March 31, 2007.

Frontier Airlines Holdings Inc. says its mainline fuel cost per gallon during the fiscal year jumped 15 percent to $2.44 from $2.12 from the previous fiscal year.