ZURICH (Reuters) - Johnson & Johnson and Actelion have asked Switzerland's takeover board about the viability of a complicated takeover deal the U.S. healthcare company is discussing with the Swiss biotech firm, newspaper Tages-Anzeiger reported on Friday, without saying how it got the information. The two companies asked about the proposal under which Johnson & Johnson would acquire Actelion while separating its commercialized portfolio from its research and development assets, a deal structure first reported by Reuters last week. The panel's preliminary review was still going on, the paper said. The Tages-Anzeiger quotes a spokesman for the takeover board as saying it does not comment on specific transactions. The Swiss takeover board, which determines whether a deal meets legal requirements, did not immediately respond to a request by Reuters for comment. An Actelion spokesman also did not immediately respond to a request for comment. The proposed deal structure would allow J&J to acquire Actelion with a cash offer in the region of $260 per share, a little more than what it had offered when it walked away from negotiations earlier in December. It also would allow Actelion shareholders to benefit financially from Actelion's R&D pipeline, people familiar with the matter told Reuters. In return for a minority stake in the remaining business to develop new drugs, Johnson & Johnson could invest $1 billion to $2 billion over several years into Actelion's research activities as part of the deal, the Tages-Anzeiger reported, again without saying where the information came from. (Reporting by Joshua Franklin; Editing by Michael Shields)