Three Months Ended

March 31,

2024

2023

U.S. defined benefit plans:

Pension benefits

Service cost of benefits earned during the period

$

0.6

$

0.7

Interest cost on projected benefit obligation

4.2

4.2

Expected return on plan assets

(6.1

)

(6.2

)

Amortization of net actuarial loss

1.3

1.3

Net periodic pension cost

$

-

$

-

Retiree health and life insurance benefits

Interest cost on projected benefit obligation

$

0.5

$

0.7

Amortization of prior service cost

(0.1

)

-

Amortization of net actuarial gain

(2.1

)

(1.5

)

Net periodic postretirement credit

$

(1.7

)

$

(0.8

)