Borrowings and Lines of Credit



(dollars in millions)	March 31, 2018		December 31, 2017
Commercial paper	$	930	$	300
Other borrowings	136		92
Total short-term borrowings	$	1,066	$	392

At March 31, 2018, we had revolving credit agreements with various banks permitting aggregate borrowings of up to $4.35 billion, pursuant to a $2.20 billion revolving credit agreement and a $2.15 billion multicurrency revolving credit agreement, both of which expire in August 2021. As of March 31, 2018, there were no borrowings under either of these agreements. The undrawn portions of these revolving credit agreements are also available to serve as backup facilities for the issuance of commercial paper. As of March 31, 2018, our maximum commercial paper borrowing limit was $4.35 billion. Commercial paper borrowings at March 31, 2018 include approximately €750 million ($930 million) of euro-denominated commercial paper. We use our commercial paper borrowings for general corporate purposes, including the funding of potential acquisitions, discretionary pension contributions, debt refinancing, dividend payments and repurchases of our common stock. The need for commercial paper borrowings arises when the use of domestic cash for general corporate purposes exceeds the sum of domestic cash generation and foreign cash repatriated to the U.S.

On February 1, 2018, we repaid at maturity the $99 million 6.80% notes due in 2018 and on February 22, 2018, we repaid at maturity the €750 million EURIBOR plus 0.80% floating rate notes due in 2018.

In connection with the merger agreement with Rockwell Collins announced on September 4, 2017, we have entered into a $6.5 billion 364-day unsecured bridge loan credit agreement that would be funded only to the extent certain anticipated debt issuances are not completed prior to the completion of the merger. See Note 1 for additional discussion.

Long-term debt consisted of the following:



(dollars in millions)	March 31, 2018			December 31, 2017
6.800% notes due 2018	—			99
EURIBOR plus 0.800% floating rate notes due 2018 (€750 million principal value) ²	—			890
1.778% junior subordinated notes due 2018	1,100			1,100
LIBOR plus 0.350% floating rate notes due 2019 ³	350			350
1.500% notes due 2019 ¹	650			650
EURIBOR plus 0.15% floating rate notes due 2019 (€750 million principal value) ²	930			890
8.875% notes due 2019	271			271
4.875% notes due 2020 ¹	171			171
4.500% notes due 2020 ¹	1,250			1,250
1.900% notes due 2020 ¹	1,000			1,000
8.750% notes due 2021	250			250
1.950% notes due 2021 ¹	750			750
1.125% notes due 2021 (€950 million principal value) ¹	1,178			1,127
2.300% notes due 2022 ¹	500			500
3.100% notes due 2022 ¹	2,300			2,300
1.250% notes due 2023 (€750 million principal value) ¹	930			890
2.800% notes due 2024 ¹	800			800
1.875% notes due 2026 (€500 million principal value) ¹	620			593
2.650% notes due 2026 ¹	1,150			1,150
3.125% notes due 2027 ¹	1,100			1,100
7.100% notes due 2027	141			141
6.700% notes due 2028	400			400
7.500% notes due 2029 ¹	550			550
5.400% notes due 2035 ¹	600			600
6.050% notes due 2036 ¹	600			600
6.800% notes due 2036 ¹	134			134
7.000% notes due 2038	159			159
6.125% notes due 2038 ¹	1,000			1,000
5.700% notes due 2040 ¹	1,000			1,000
4.500% notes due 2042 ¹	3,500			3,500
4.150% notes due 2045 ¹	850			850
3.750% notes due 2046 ¹	1,100			1,100
4.050% notes due 2047 ¹	600			600
Project financing obligations	175			158
Other (including capitalized leases)	197			195
Total principal long-term debt	26,306			27,118
Other (fair market value adjustments and discounts)	(25		)	(25		)
Total long-term debt	26,281			27,093
Less: current portion	1,128			2,104
Long-term debt, net of current portion	$	25,153		$	24,989


1	We may redeem these notes at our option pursuant to their terms.


2	The three-month EURIBOR rate as of March 31, 2018 was approximately -0.328%. The notes may be redeemed at our option in whole, but not in part, at any time in the event of certain developments affecting U.S. taxation.


3	The three-month LIBOR rate as of March 31, 2018 was approximately 2.312%.

The average maturity of our long-term debt at March 31, 2018 is approximately 12 years. The average interest expense rate on our total borrowings for the quarters ended March 31, 2018 and 2017 were as follows:



	Quarter Ended March 31,
	2018		2017
Average interest expense rate	3.4	%	3.5	%

We have an existing universal shelf registration statement filed with the Securities and Exchange Commission (SEC) for an indeterminate amount of equity and debt securities for future issuances, subject to our internal limitations on the amount of equity and debt to be issued under this shelf registration statement.