6. EMPLOYEE BENEFITS

Pension Plan

We maintain a qualified defined benefit pension plan (“Pension Plan”), which covers eligible current and former employees and has been frozen since March 31, 2009. No new participants may enter the Pension Plan and no further benefits will accrue. However, years of service continue to count toward early retirement calculations and vesting of benefits previously earned.

We also have a limited number of supplemental retirement plans to provide certain key current and former employees with additional retirement benefits. These plans are funded on a pay-as-you-go basis and the accrued pension obligation is largely included in other long-term obligations.

The elements of retirement benefit expense are as follows:


	Quarters Ended				Six Months Ended
	July 1,		June 25,		July 1,		June 25,
(in thousands)	2018		2017		2018		2017
Pension plans:
Interest Cost		19,789		21,367	$	39,577	$	42,734
Expected return on plan assets		(22,624)		(22,393)		(45,248)		(44,785)
Actuarial loss		6,296		5,084		12,591		10,168
Net pension expense		3,461		4,058		6,920		8,117
Net post-retirement benefit credit		(682)		(730)		(1,363)		(1,462)
Net retirement benefit expenses	$	2,779	$	3,328	$	5,557	$	6,655

In May 2018, the Pension Plan sold the Lexington real property for approximately $4.1 million and we terminated our lease on the property. The property was included in the real property contributions that we made to the Pension Plan in fiscal year 2011. As a result of the sale by the Pension Plan, we recognized a $0.2 million loss on the sale of the Lexington property in the other operating expenses on the condensed consolidated statement of operations for the quarter and six months ended July 1, 2018.

401(k) Plan

We have a deferred compensation plan (“401(k) plan”), which enables eligible employees to defer compensation. During the fourth quarter of 2017, we announced the reinstatement of a company matching contribution program beginning with the first pay check paid in 2018. Our matching contributions in the quarter and six months ended July 1, 2018, were $0.6 million and $1.3 million, respectively, and are recorded in our compensation line item of our condensed consolidated statement of operations. Also during the fourth quarter of 2017, we terminated the 401(k) plan supplemental contribution that was tied to performance.