JERUSALEM, Jan 1 (Reuters) - Israeli medical device company CollPlant Holdings said on Thursday it was working to register its shares in the United States to attract American and foreign investors.

CollPlant, which produces medicines from plant-derived collagen, a protein vital for tissue repair, said its first level American Depository Receipts (ADRs) would be traded over the counter (OTC).

It noted that the process could take a few weeks to a few months.

CollPlant recently began a clinical trial for a gel to heal chronic wounds, such as diabetic ulcers, surgical wounds and burns. The trial is expected to end in the first quarter of 2015 and the company said that immediately thereafter it would apply to European regulators for approval to start selling the product in the second half of the year.

It noted the global market for advanced wound care is about $5 billion.

CollPlant said it also plans to apply for European regulatory approval by the third quarter of 2015 to sell a product to treat tendonitis. The market in Europe is worth about $2 billion, it said.

The company said that after sales begin in Europe, it would seek U.S. regulatory approval to sell in the United States.

(Reporting by Steven Scheer; Editing by Ruth Pitchford)