DUESSELDORF  - Thyssenkrupp is keeping its options open regarding the prospective sale of its steel and plant divisions, the management board said in a letter to staff on Friday, adding that the outcome of talks was unclear.

"We are a long way from our goal and will have to go further through the 'red zone'," read the letter reviewed by Reuters that called on the German industrial conglomerate's workforce to be patient.

Essen-based Thyssenkrupp is considering a non-binding offer for its loss-making steel unit from commodities tycoon Sanjeev Gupta's Liberty Steel. It is also exploring sale options for its Multi-Track plant unit.

"We are in the middle of a process that contains multiple options," the letter said, adding that this strategy has helped secure a high price in the sale of its profitable elevators unit earlier this year.

"From our point of view, it is right to keep our options open for a long time."

(Reporting by Tom Kaeckenoff, Writing by Douglas Busvine, Editing by Thomas Escritt)