The following table reconciles free cash flow to net cash flows provided by operating activities. Cash deposits are maintained to provide credit enhancement for certain agreements and are reported as part of cash and  cash equivalents. For most of these deposits, the cash may be withdrawn if a comparable security is provided in the form of  letters of credit. Accordingly, these deposits are not considered to be restricted. Marketable securities are included as a component of global liquidity as these investments can be readily liquidated at our  discretion. The components of our December 31, 2014 consolidated cash balance were as follows: Cash and marketable securities of $159 held by a wholly-owned subsidiary , Dana Companies, LLC, at December 31, 2014  can be transferred out of this subsidiary only if approved by its independent board member . Accordingly, accessing this  component of global liquidity is uncertain. A portion of the non-U.S. cash and cash equivalents is utilized for working capital and other operating purposes. Several  countries have local regulatory requirements that significantly restrict the ability of our operations to repatriate this cash.  Beyond these restrictions, there are practical limitations on repatriation of cash from certain subsidiaries because of the  resulting tax withholdings and subsidiary by-law restrictions which could limit our ability to access cash and other assets. The principal sources of liquidity available for our future cash requirements are expected to be (i) cash flows from  operations, (ii) cash and cash equivalents on hand and (iii) borrowings from our revolving facility . We believe that our overall  liquidity and operating cash flow will be suf ficient to meet our anticipated cash requirements for capital expenditures, working  capital, debt obligations, common stock repurchases and other commitments during the next twelve months.  While uncertainty  surrounding the current economic environment could adversely impact our business, based on our current financial position, we  believe it is unlikely that any such ef fects would preclude us from maintaining suf ficient liquidity. At December 31, 2014, we had no borrowings under the revolving facility but we had utilized $44 for letters of credit.  Based on our borrowing base collateral, we had availability as of that date under the revolving facility of $303 after deducting  the outstanding letters of credit. In December 2014, we completed the sale of $425 in senior unsecured notes. Net proceeds of the of fering after transaction  costs totaled $418. Net proceeds of $359 were used to redeem $345 of our senior notes due February 15, 2019 (February 2019  Notes) pursuant to a tender of fer at a weighted average price of 104.1 16%. In January 2015, net proceeds of $41 were used to  U.S. Non-U.S. Total Cash and cash equivalents $ 504 $ 479 $ 983 Cash and cash equivalents held as deposits 2 20 22 Cash and cash equivalents held at less than wholly-owned subsidiaries 2 114 116 Consolidated cash balance $ 508 $ 613 $ 1,121 30 2014 2013 2012 Net cash provided by operating activities $ 510 $ 577 $ 339 Purchases of property, plant and equipment (234 ) (209 ) (164 ) Free cash flow $ 276 $ 368 $ 175 Liquidity Our global liquidity at December 31, 2014 was as follows: Cash and cash equivalents $ 1,121 Less: Deposits supporting obligations (22 ) Available cash 1,099 Additional cash availability from revolving facility 303 Marketable securities 169 Total global liquidity $ 1,571