VIENNA (Reuters) - Drugmaker Novartis <NOVN.S> is considering to sell its struggling Alcon eye care division, its chairman said in an interview with Swiss weekly SonntagsZeitung.

Novartis has blamed a failure to innovate and inconsistent customer service for the problems at Alcon, a business the company gradually bought from food maker Nestle in deals totaling $51 billion.

Alcon will take longer to turn around than expected, Chief Executive Joe Jimenez said in October, forecasting unit sales to be flat to slightly down in the current quarter.

"Alcon has not developed over the past two years as we had expected," Chairman Joerg Reinhardt said in an interview published on Sunday. Even though Novartis would continue to push the turnaround, all options were open in the future.

"In the long run, the question arises as to whether we are the best owner for Alcon."

(Reporting by Kirsti Knolle; Editing by Raissa Kasolowsky)