FRANKFURT/DUESSELDORF (Reuters) - The owners of German medical skin patch maker LTS Lohmann have invited Evonik (>> Evonik Industries AG) to make a new bid for the company after finding final offers from other bidders unsatisfactory, three sources familiar with the deal said.

Evonik will now work on a new offer, which could be approved by its supervisory board in the coming weeks, the sources said.

The German speciality chemicals and plastics maker a few months ago dropped out of the race for LTS Lohmann, but over the last couple of days was approached by sellside advisor Morgan Stanley and asked to hand in a fresh bid, the sources said.

LTS Lohmann's owners had proceeded with other bidders and last month narrowed the field to private equity groups Wendel of France and Nordic Capital of Sweden, which were willing to value LTS Lohmann at 1.2 billion euros (1.00 billion pounds).

But the owners - Swiss drugmaker Novartis (>> Novartis AG), German billionaire Dietmar Hopp and German investment company BWK - could not agree on whether this should be considered satisfactory.

Evonik, BWK and Morgan Stanley declined to comment. Novartis and Hopp's investment company were not immediately available for comment.

(Reporting by Arno Schuetze and Matthias Inverardi; Editing by Harro ten Wolde)

By Arno Schuetze and Matthias Inverardi