A lender that provided a mortgage for 220 acres of development sites at Union Point took possession from master developer LStar Ventures on Wednesday, submitting the high bid of $18 million at a public auction.

The lots are zoned for up to 8 million square feet of commercial development, according to Daniel P. McLaughlin Auctioneers & Co. of Boston. RFM-UBC High Yield Fund II LLC provided a $48 million mortgage in 2017.

Raleigh, North Carolina-based LStar is on the verge of being removed as master developer at the 1,450-acre former South Weymouth Naval Air Station amid financial difficulties and legal battles among executives.

Boston-based Washington Capital Management bid $33.2 million for 115 acres at Union Point last month that are zoned for more than 3,300 residential units.

The Southfield Redevelopment Authority, a regional public agency which oversees the property, has notified LStar that it’s in default of the master development agreement and faces removal from its role by March 22.

Approximately 1,000 residential units have been built at the former air base which closed in 1997, but attempts to attract commercial development have stalled. Prodrive Technologies, a Dutch robotics company, pulled out of a deal to build a 300,000-square-foot U.S. headquarters at Union Point in December. That decision came after Weymouth Mayor Robert Hedlund notified LStar that the town would not provide the property with water service for future development.

In a related matter, Boston-based Elkus Manfredi Architects is seeking $1 million from LStar Ventures for services it provided on the project. The civil suit in Norfolk Superior Court claims LStar failed to pay for designs including the Union Point Sports Complex, The Patriot Ledger reported this week.