Jan 8 (Reuters) - Johnson & Johnson on Wednesday said it submitted a citizen petition asking that U.S. health regulators require copies of biological products to bear names that are similar and not identical to those of their reference products.

J&J's view on naming of biosimilars contrasts that of Mylan Inc and Novartis AG over the past few months, as the U.S. Food and Drug Administration continues to work on drafting regulations for the approval of biosimilars -- cheaper versions of expensive biologics, or the original reference drugs.

"Assigning names that are similar but not the same will appropriately reflect the legal and scientific reality that biosimilars are similar to but not the same as their reference products or other biosimilars," J&J's Chief Biotechnology Officer Jay Siegel said in a statement.

Creating copies of biologics is complicated as these products are produced in living cells, bringing inevitable unpredictability. As a result, their copies can only ever be "similar," not exact replicas.

Names of biosimilars are also bound to impact their sales and adoption as substitutes to the original products.

Novartis and Mylan have both previously expressed support for a system that requires that a biosimilar share the same international non-proprietary name (INN) as the biologic products to which it refers, saying that same names would avoid frivolous brand tactics and confusion in the marketplace.

Mylan in September said it supported a petition filed by the Washington, DC-based Generic Pharmaceutical Association that recommended biosimilars have the same names because by definition they are highly similar to their reference products and have no meaningful differences that require a unique name.

Novartis advocated for the same by filing its own petition in October.

Biologic medicines, typically administered via an injection, and are used to treat cancers, immunological diseases like rheumatoid arthritis and multiple sclerosis and other chronic illnesses, but their high price tag can keep them out of reach for many patients.

The FDA in February 2012 issued draft guidance on approval pathways for biosimilars, but is yet to finalize that guidance, while European regulators have already cleared cheaper copies of some biotech medicines.

The global biosimilars market is expected to be worth about $11 billion to $25 billion in 2020, equivalent to a modest 4 to 10 percent of total biotech drug sales by that time, according to healthcare information firm IMS Health.