(millions)

Pension Benefits

Other Postretirement Benefits

Three Months Ended September 30,

2023

2022

2023

2022

Service cost

$

2

$

2

$

—

$

—

Interest cost

8

5

2

1

Expected return on assets

(8

)

(12

)

—

—

Amortization of actuarial losses

3

1

(1

)

—

Net periodic benefit cost (credit)

$

5

$

(4

)

$

1

$

1

Nine Months Ended September 30,

Service cost

$

6

$

6

$

1

$

1

Interest cost

24

16

6

4

Expected return on assets

(25

)

(37

)

—

—

Amortization of actuarial losses

9

1

(3

)

—

Net periodic benefit cost (credit)

$

14

$

(14

)

$

4

$

5