FRANKFURT (Reuters) - German companies need to diversify their funding as the implementation of new bank safety rules makes it harder for banks to provide loans, Deutsche Bank (DBK.DE) co-Chief Executive Juergen Fitschen told Germany's Boersen Zeitung.

"Companies need to prepare for greater uncertainty when it comes to the availability of bank loans and should strengthen their resilience," Fitschen said in an opinion piece published in Saturday's edition of Boersen Zeitung.

Pressure on banks to cut down the size of their balance sheets, and the need to set aside more money for problem loans, means corporations should use capital market instruments, such as issuing shares and bonds, as a way to raise funds, Fitschen said.

(Reporting by Edward Taylor; Editing by Louise Heavens)