MPLX is a publicly traded master limited partnership that was formed by us to own, operate, develop and acquire pipelines and other midstream assets related to the transportation and storage of crude oil, refined products and other hydrocarbon-based products. In October 2012, MPLX completed its initial public offering of 19,895,000 common units. Net proceeds to MPLX from the sale of the units were $407 million. We own a 73.6 percent interest in MPLX, including the two percent general partner interest. We consolidate this entity for financial reporting purposes since we have a controlling financial interest, and we record a noncontrolling interest for the interest owned by the public. The initial public offering represented the sale of a 26.4 percent interest in MPLX.
MPLX's initial assets consisted of a 51 percent general partner interest in MPLX Pipe Line Holdings LP ("Pipe Line Holdings"), which owns a network of common carrier crude oil and product pipeline systems and associated storage assets in the Midwest and Gulf Coast regions of the United States, and a 100 percent interest in a butane storage cavern in West Virginia. On May 1, 2013, we sold an additional five percent interest in Pipe Line Holdings to MPLX for $100 million, increasing MPLX's ownership interest in Pipe Line Holdings to 56 percent and reducing our ownership to 44 percent.
On February 27, 2014, we announced the sale of an additional 13 percent interest in Pipe Line Holdings to MPLX for $310 million, effective March 1, 2014. Subsequent to this transaction, MPLX will own a 69 percent general partner interest in Pipe Line Holdings and we will own a 31 percent limited partner interest. MPLX intends to finance this transaction with $40 million of cash on-hand and by borrowing $270 million on its revolving credit agreement.
MPLX generates revenue primarily by charging tariffs for transporting crude oil, refined products and other hydrocarbon-based products through their pipelines and at their barge dock and fees for storing crude oil and products at their storage facilities. They are also the operator of additional crude oil and product pipelines owned by us and third parties for which they are paid operating fees. They do not take ownership of the crude oil or products that they transport and store for their customers, and they do not engage in the trading of any commodities.
We have entered into nine long-term, fee-based transportation agreements and five long-term, fee-based storage services agreements with MPLX. Under these agreements, MPLX provides transportation and storage services to us, and we commit to provide MPLX with minimum quarterly throughput and storage volumes of crude oil and products and minimum storage volumes of butane. These agreements range from three to ten years in length, and most automatically renew unless terminated by either party. We believe the terms and conditions under these commercial agreements, as well as the other initial agreements we entered into with MPLX are generally no less favorable to either party than those that could have been negotiated with unaffiliated parties with respect to similar services.
Under the transportation services agreements, if we fail to transport our minimum throughput volumes during any quarter, then we will pay MPLX a deficiency payment equal to the volume of the deficiency multiplied by the tariff rate then in effect. Any such deficiency payments may then be applied as a credit for volumes transported on the applicable pipeline system in excess of its minimum volume commitment during the following four or eight quarters under the terms of the applicable transportation services agreement. As of December 31, 2013, we had $34 million in volume deficiency credits. If the minimum capacity of the pipeline falls below the level of our commitment at any time or if capacity on the pipeline is required to be allocated among shippers because volume nominations exceed available capacity, depending on the cause of the reduction in capacity, our commitment may be reduced or we will receive a credit for our minimum volume commitment for that period. In addition to our minimum volume commitment, we are responsible for any loading, handling, transfer and other charges with respect to volumes MPLX transports for us. If MPLX agrees to make any capital expenditures at our request, we will reimburse MPLX for, or MPLX will have the right in certain circumstances, to file for an increased tariff rate to recover the actual cost of such capital expenditures. The transportation services agreements include provisions that permit us to suspend, reduce or terminate our obligations under the applicable agreement if certain events occur. These events include us deciding to permanently or indefinitely suspend refining operations at one or more of our refineries for at least twelve consecutive months and certain force majeure events that would prevent MPLX or us from performing under the applicable agreement.
Under the storage services agreements, MPLX is obligated to make available to us on a firm basis the available storage capacity at the tank farms and butane cavern, and we pay MPLX a per-barrel fee for such storage capacity, regardless of whether we fully utilize the available capacity. Beginning on January 1, 2014, the storage services agreements are adjusted based on changes in the producer price index.
At the closing of the initial public offering of MPLX, we entered into an operating services agreement with MPLX under which MPLX operates various pipeline systems owned by us. In addition, under existing operating service agreements, MPLX continues to operate various pipeline systems owned by us and third parties. Under these operating services agreements MPLX receives an operating fee for operating the assets and is reimbursed for all direct and indirect costs associated with operating the assets. The operating fees under most of these agreements are indexed for inflation. These agreements range from one to five years in length and automatically renew unless terminated by either party.
Management Services Agreements
Prior to the closing of the initial public offering of MPLX, MPLX entered into two management services agreements with us under which MPLX provides certain management services to us with respect to certain of our retained pipeline assets. MPLX receives fixed annual fees under the agreements for providing the required management services, which is adjusted annually for inflation and based on changes in the scope of management services provided.
Upon the closing of the initial public offering of MPLX, we entered into an omnibus agreement with MPLX that addresses MPLX’s payment of a fixed annual fee to us for the provision of executive management services and MPLX’s reimbursement to us for the provision of certain general and administrative services to MPLX, as well as our indemnification of MPLX for certain matters, including environmental, title and tax matters.
Employee Services Agreements
Prior to the closing of the initial public offering of MPLX, we entered into two employee services agreements with MPLX under which MPLX reimburses us for the provision of certain operational and management services in support of their pipelines, barge dock, butane cavern and tank farms.