UPDATE 1-Cablevision not selling assets, may spin off MSG

* Cablevision says not selling off Madison Square Garden

* Cablevision says exploring spin-off of MSG to holders

* Shares down 1 pct.

NEW YORK, May 11 (Reuters) - Cablevision Systems Corp (CVC.N) on Monday said it has no plans to sell its Madison Square Garden unit or any other assets but repeated it is exploring a plan to spin off the unit to its shareholders.

The New York cable operator stirred investors on Thursday after it said it is exploring spinning off MSG, which holds assets like the New York Knicks basketball team and Radio City Music Hall.

The vague wording in Thursday's statement and a later refusal by Cablevision's management to provide further details on a conference call with analysts led to speculation that the company is planning to sell off its assets.

But in a terse statement on Monday Cablevision attempted to clarify that the MSG unit was considering a spin-off to its shareholders and tried to end speculation of a sale.

"The company feels it should make clear that it is not considering the sale of MSG, any of MSG's businesses or any other Cablevision business at this time," the statement said on Monday.

The distinction between an MSG sale and an MSG spin-off is that Cablevision shareholders, led by the Dolan family, would still own the MSG unit as a separate company in the event of a spin-off. A person familiar with the plans said a spun-off MSG could have a "mirror ownership structure" to Cablevision.

Last week Cablevision's shares rose as much as 18 percent on the possibility that the MSG spin-off could be the first stage in a long-expected break-up of Cablevision, although shares eventually retreated.

Its various assets include sports franchises, entertainment venues, cable networks and cable systems that reach around 5 million homes in the New York area.

Shares in Cablevision dipped by 14 cents to $19.32 on the New York Stock Exchange. (Reporting by Yinka Adegoke)