Celebrity dermatologist Dr. Zein Obagi has sued the company he founded, alleging that publicly traded Obagi Medical Products Inc. engaged in anti-competitive practices that hurt a private company he later founded.

Obagi Medical of Long Beach said that it was served with the suit on Thursday and intends to vigorously defend itself against the claims.

Dr. Obagi said he gave Obagi Medical Products first right of refusal to market his new line of skin care products. But Obagi Medical, which hasn’t been controlled by Dr. Obagi since 1997, turned him down. Dr. Obagi alleges that Obagi Medical sought to block the marketing of the products and the sale of his new company.

The complaint filed in the Los Angeles County Superior Court seeks unspecified damages and injunctive relief, with Dr. Obagi demanding arbitration.

Obagi Medical shares were down 47 cents, or nearly 4 percent, to $11.67 in midday trading on the Nasdaq.