Tesoro Hawaii’s plan to lay off most of its Kapolei refinery workers, which was delayed last month as the company negotiated with a potential buyer, was set in motion Monday with a first group of employees getting notices that they would lose their jobs within three weeks.

"A small group received notices today," said Lance Tanaka, Tesoro Hawaii’s manager of government and public affairs. Some of the employees who received notices Monday will be laid off June 17 and others on June 21, Tanaka said.

Tanaka added that the company remained in discussions with interested parties to sell the refinery, which once employed 240. If a buyer is found, some of the workers might continue with the new owner, Tanaka said.

Tesoro Hawaii filed a notice with the state May 10 saying the company plans to lay off 165 workers in three phases starting June 14. Tanaka said the employees notified Monday were the initial group, which he described as just a "handful." A second group will be laid off starting June 28 and a third group starting July 12, according to Tesoro’s May 10 notice. Tanaka said the refinery intends to give any employee laid off at least two weeks’ notice.

Tesoro initially informed the state Department of Labor and Industrial Relations in February that it planned to close the refinery and begin laying off workers May 1. But when that day arrived, Tesoro officials announced that they were postponing the layoffs while pursuing negotiations with a potential buyer or buyers that would continue operations at the state’s largest oil refinery.

Tesoro — which is headquartered in San Antonio — ceased refining operations at the Kapolei plant April 30 and began converting it into an import, storage and distribution terminal for refined petroleum products. The company also began "mothballing" activities to preserve the oil refining equipment for future use in the event the refinery is sold.

The employees given notices Monday were workers who are not needed for the conversion or "mothballing" job, Tanaka said.

Tanaka said some employees in Hawaii had been anticipating transferring to the mainland with Tesoro. "Those people have been asked to hold off" until the situation with the potential buyer is settled, Tanaka said.

Tesoro, the largest of two refineries in Hawaii, announced in January 2012 that it planned to sell the refinery. The other refinery is owned by Chevron Corp., which is based in San Ramon, Calif. Tesoro’s refinery can process up to 94,000 barrels a day. Chevron can process 54,000 barrels.

Tesoro is also trying to sell its chain of 31 gas stations and roughly 20 attached convenience stores in Hawaii.