San Diego-based PS Group, the former parent...

San Diego-based PS Group, the former parent company of Pacific Southwest Airlines, has sold about 65% of its oil and gas business assets to Graham Royalty, the companies said Wednesday. PS Group will report a $16-million gain from the sale.

PS Group’s oil and gas business consists largely of producing and undeveloped resources in Texas.

The proposed sale will be completed in mid-April. Graham will assume PS Group’s “take-or-pay” oil- and gas-purchase contracts, which carry a $17-million liability. PS Group will use proceeds of the sale to reduce its debt.