* K+S discussed state intervention with minister-paper
* Stake purchase by state development bank discussed-paper
* Nationalisation seen as unlikely (Adds source on KfW not acting as white knight)
FRANKFURT, July 29 (Reuters) - German potash and salt miner K+S has turned to economy minister Sigmar Gabriel for help in resisting an unwanted takeover approach by Potash Corp of Saskatchewan Inc, and has discussed the option of German state bank KfW taking a stake in K+S, a newspaper reported on Wednesday.
K+S earlier this month rebuffed Potash Corp's 7.9 billion euros ($8.7 billion) proposed bid of 41 euros per share as too low and suggested the suitor was planning to shrink the company.
K+S last week said it had rejected a new attempt by its Canadian suitor, which is due to report second-quarter results on Thursday, to entice it into takeover talks.
KfW could take a blocking minority stake but Germany's economy ministry and finance ministry are doubtful they could come up with a "common-good" justification for such an intervention, Handelsblatt cited people familiar with the matter as saying.
K+S declined to comment while the economy ministry only said there had been talks with the company about a "corporate matter" and would not comment further.
A person familiar with the matter told Reuters that state development bank KfW had never before acted as a "white knight" to scupper a takeover and was unlikely to play such a role. (Reporting by Kathrin Jones and Ludwig Burger in Frankfurt, Michelle Martin in Berlin; Editing by Muralikumar Anantharaman and Mark Potter)