ON Semiconductor Corp., the Phoenix company seeking to buy Fairchild Semiconductor International Inc., including its Maine operations, reported a decline in revenue and net income for the first quarter compared with a year earlier.

ON generated revenue of $817.2 million in the first quarter, down 6.2 percent from $870.8 million a year earlier, the company reported Monday. Net income for the quarter was $36 million, or 9 cents a share, down 29.2 percent from $55.1 million, or 13 cents a share, in the first quarter of 2015.

Net income in the first quarter was affected negatively by $34.3 million in special costs not related to operational expenses, such as a $23.7 million write-down of acquisition-related intangible assets.

ON Semiconductor offered to buy San Jose, California-based Fairchild for $2.4 billion in November, but the deal has yet to close. According to the U.S. Securities and Exchange Commission, in late April the parties requested an extension of the offer to May 12, which is Thursday.

Fairchild operates a production facility in South Portland that employs more than 500 workers. The plant on Western Avenue is part of Fairchild’s Analog Power Signal and Solutions Division, and makes analog switches, USB, converters and other building blocks of digital circuitry. The company sells components used in cars, smartphones, appliances and other consumer products. It reported revenue of $1.37 billion in 2015.

A Chinese investment group also had made a bid for Fairchild, offering $21.70 per share, which topped ON’s offer of $20 per share. But in February, Fairchild management declined the offer from China Resources Microelectronics Ltd. and Hua Capital Management Co. without specifying why.

Analysts surmised it was because the deal would not receive U.S. regulators’ blessing.