DEBT

The following table sets forth our consolidated debt for the periods indicated:



	June 30, 2018			December 31, 2017
	(Thousands of dollars)
Commercial paper outstanding, bearing a weighted-average interest rate of 2.66% and 2.23% as of June 30, 2018, and December 31, 2017, respectively.	$	156,000		$	614,673
Senior unsecured obligations:
$425,000 at 3.2% due September 2018	425,000			425,000
$1,000,000 term loan, rate of 2.87% as of December 31, 2017, due January 2019	—			500,000
$500,000 at 8.625% due March 2019	500,000			500,000
$300,000 at 3.8% due March 2020	300,000			300,000
$700,000 at 4.25% due February 2022	547,397			547,397
$900,000 at 3.375 % due October 2022	900,000			900,000
$425,000 at 5.0 % due September 2023	425,000			425,000
$500,000 at 7.5% due September 2023	500,000			500,000
$500,000 at 4.9 % due March 2025	500,000			500,000
$500,000 at 4.0% due July 2027	500,000			500,000
$100,000 at 6.875% due September 2028	100,000			100,000
$400,000 at 6.0% due June 2035	400,000			400,000
$600,000 at 6.65% due October 2036	600,000			600,000
$600,000 at 6.85% due October 2037	600,000			600,000
$650,000 at 6.125% due February 2041	650,000			650,000
$400,000 at 6.2% due September 2043	400,000			400,000
$700,000 at 4.95% due July 2047	700,000			700,000
Guardian Pipeline
Weighted average 7.85% due December 2022	32,782			36,607
Total debt	8,236,179			9,198,677
Unamortized portion of terminated swaps	17,609			18,468
Unamortized debt issuance costs and discounts	(73,892		)	(78,193		)
Current maturities of long-term debt	(932,650		)	(432,650		)
Short-term borrowings (a)	(156,000		)	(614,673		)
Long-term debt	$	7,091,246		$	8,091,629

(a) - Individual issuances of commercial paper under our commercial paper program generally mature in 90 days or less. These issuances are supported by and reduce the borrowing capacity under our $2.5 Billion Credit Agreement.

$2.5 Billion Credit Agreement - In June 2018, we extended the term of our $2.5 Billion Credit Agreement by one year to June 2023. Our $2.5 Billion Credit Agreement is a $2.5 billion revolving credit facility and contains certain financial, operational and legal covenants. Among other things, these covenants include maintaining a ratio of indebtedness to adjusted EBITDA (EBITDA, as defined in our $2.5 Billion Credit Agreement, adjusted for all noncash charges and increased for projected EBITDA from certain lender-approved capital expansion projects) of no more than 5.5 to 1 at June 30, 2018, and 5.0 to 1 thereafter. Once the covenant decreases to 5.0 to 1, if we consummate one or more acquisitions in which the aggregate purchase is $25 million or more, the allowable ratio of indebtedness to adjusted EBITDA will increase to 5.5 to 1 for the quarter in which the acquisition is completed and the two following quarters.

Our $2.5 Billion Credit Agreement includes a $100 million sublimit for the issuance of standby letters of credit and a $200 million sublimit for swingline loans. Under the terms of our $2.5 Billion Credit Agreement, we may request an increase in the size of the facility to an aggregate of $3.5 billion by either commitments from new lenders or increased commitments from existing lenders. Our $2.5 Billion Credit Agreement contains provisions for an applicable margin rate and an annual facility fee, both of which adjust with changes in our credit ratings. Based on our current credit ratings, borrowings, if any, will accrue at LIBOR plus 110 basis points, and the annual facility fee is 15 basis points. We have the option to request an additional one-year extension, subject to lender approval, which may be used for working capital, capital expenditures, acquisitions and mergers, the issuance of letters of credit and for other general corporate purposes. At June 30, 2018, we had no borrowings outstanding, our ratio of indebtedness to adjusted EBITDA was 3.5 to 1, and we were in compliance with all covenants under our $2.5 Billion Credit Agreement.

Debt Issuances - In July 2018, we completed an underwritten public offering of $1.25 billion senior unsecured notes consisting of $800 million, 4.55 percent senior notes due 2028 and $450 million, 5.20 percent senior notes due 2048. The net proceeds, after deducting underwriting discounts, commissions and offering expenses, were $1.23 billion. The proceeds will be used for general corporate purposes, which may include repayment of existing indebtedness and funding capital expenditures.

Debt Repayments - In January 2018, we repaid the remaining $500 million balance outstanding on the Term Loan Agreement due 2019 with a combination of cash on hand and short-term borrowings.

Debt Guarantees - Effective June 30, 2017, with the Merger Transaction, we, ONEOK Partners and the Intermediate Partnership issued, to the extent not already in place, guarantees of the indebtedness of ONEOK and ONEOK Partners.