LOS ANGELES (AP) – A proposed deal to acquire media giant NBC Universal would give current owner General Electric Co. the ability to unwind its stake over several years, and could see Comcast Corp. commit billions more to the joint venture, a person close to the situation said Monday.

GE would be allowed to redeem some portion of its 49 percent stake for cash after 3.5 years, and again after 7 years, said the person, who was not authorized to speak publicly about the negotiations and spoke on condition of anonymity.

The cash would be generated by NBC Universal's operations, although Comcast has agreed it could provide up to "mid-single billions" of dollars to backstop the purchase of GE's remaining stake, the person said . Buying GE's remaining stake would not be mandatory, however, the person added.

Any money Comcast ends up putting toward buying out GE's stake would be on top of the estimated $6 billion in cash, plus its cable network assets that it is already committing to the companies' venture. The total value of the proposed joint venture between Comcast and GE is estimated around $30 billion, and it would carry about $9 billion in debt.

The joint venture arrangement is being discussed as a way for Philadelphia-based Comcast to gain majority control of NBC Universal, which is currently owned 80 percent by GE and 20 percent by Vivendi SA of France.

Vivendi has an annual window to sell off its minority position, and this year that opportunity falls between Nov. 15 and Dec. 10.

Vivendi CEO Jean-Bernard Levy has called the stake "non-core." If Vivendi does sell, GE is expected to buy the stake and contribute those shares to the NBC Universal spin-off.

As speculation heated up over Vivendi's intentions earlier this year, Comcast entered into talks with GE to purchase the content giant, which owns the NBC television network, Telemundo, Universal Studios theme parks and the Universal Pictures movie studio. NBC Universal also owns the cable networks Bravo, USA and CNBC.

The structure allowing Fairfield, Conn.-based GE to unwind its stake over a number of years was reported earlier by CNBC.

CNBC also reported that News Corp. and Liberty Media Corp. were interested in buying NBC Universal but had not begun talks with GE.

Spokespeople for News, Liberty, GE and Comcast declined to comment.

Comcast shares fell 27 cents to close at $15.28 on Monday. GE shares rose 15 cents to close at $16.33.