Lake Forest-based Quantum Fuel Systems Technologies Worldwide Inc. was purchased by Douglas Acquisitions LLC, an affiliate of second-position secured creditors.

The financial terms of the transaction, which closed in April, weren’t disclosed.

Quantum filed for Chapter 11 bankruptcy protection in late March and sought a buyer through a “363” sale process, which is essentially an asset sale, according to a filing with the United States Bankruptcy Court for the Central District of California in Santa Ana.

The filing came after two debt defaults.

Quantum secured a $6 million debtor-in-possession finance commitment from Northern California-based Douglas through court approvals before the buy.

The company will be renamed Quantum Fuel Systems LLC.

Douglas representatives didn’t immediately respond to inquiries regarding local impact.

Quantum, which has shifted its strategy from a variety of renewable energy business lines to primarily producing and selling natural fuel tanks, recently received a delisting notice from NASDAQ, as its share price has traded under $1 since mid-November.

Its ongoing struggles highlight the financial challenges facing energy-related companies; several have filed for bankruptcy in the past few years.