held at major banks, Tier-1 commercial paper, corporate notes, and certain other securities. The increase in cash, cash equivalents and marketable securities at May 31, 2013 in comparison to May 31, 2012 was due to an increase in cash generated from our operating activities, our issuance of $5.0 billion of senior notes in October 2012, and to a lesser extent, cash proceeds from fiscal 2013 stock option exercises. This increase was partially offset by $11.0 billion of repurchases of our common stock, $3.3 billion of net cash paid for acquisitions, the repayments of $1.7 billion of short-term borrowings pursuant to our expired revolving credit facilities, the repayment of $1.25 billion of senior notes which matured in April 2013, and the payment of cash dividends to our stockholders. Cash, cash equivalents and marketable securities included $28.2 billion held by our foreign subsidiaries as of May 31, 2013. We consider $26.2 billion of our undistributed earnings as indefinitely reinvested in our foreign operations outside the United States. These undistributed earnings would be subject to U.S. income tax if repatriated to the United States. Assuming a full utilization of the foreign tax credits, the potential deferred tax liability associated with these undistributed earnings would be approximately $8.0 billion as of May 31, 2013 should the amounts be repatriated to the United States. The amount of cash, cash equivalents and marketable securities that we report in U.S. Dollars for a significant portion of the cash held by our foreign subsidiaries is subject to translation adjustments caused by changes in foreign currency exchange rates as of the end of each respective reporting period (the offset to which is recorded to accumulated other comprehensive (loss) income in our consolidated balance sheets and is also presented as a line item in our consolidated statements of comprehensive income included elsewhere in this Annual Report). As the U.S. Dollar strengthened against certain major international currencies during fiscal 2013, the amount of cash, cash equivalents and marketable securities that we reported in U.S. Dollars for these subsidiaries decreased as of May 31, 2013 relative to what we would have reported using constant currency rates from our May 31, 2012 balance sheet date.

The increase in cash, cash equivalents and marketable securities at May 31, 2012 in comparison to May 31, 2011 was primarily due to an increase in cash generated from our operating activities and our short-term borrowings of $1.7 billion made pursuant to a revolving credit agreement, which expired in fiscal 2013. These increases in cash, cash equivalents and marketable securities were partially offset by our June 2011 repayment of $1.15 billion of short-term borrowings pursuant to certain expired revolving credit facilities, $255 million of cash used to repay RightNow’s legacy convertible notes after the closing of the acquisition, the use of $4.7 billion of net cash for acquisitions, the repurchases of our common stock and the payment of cash dividends to our stockholders. Additionally, cash, cash equivalents and marketable securities balances decreased as of May