Accumulated other comprehensive loss, at beginning of period

Unrealized loss on marketable securities, net of income tax effect of $1 million and $1 million

Reclassification of realized gain on marketable securities to net income, net of income tax effect of $4 million

Post employment and postretirement benefit plans:

Recognition of net actuarial (gain) loss, net of income tax effect of $17 million and $12 million

Prior service cost, net of income tax effect of less than $1 million and less than $1 million

Accumulated other comprehensive loss, at end of period