Shares of pharmaceutical companies that make emergency contraception increased Thursday after a federal appeals court issued a decision that would increase its availability.

A federal appeals court in New York on Wednesday decided to permit girls of any age to buy generic versions of emergency contraception without prescriptions while the federal government appeals a judge's ruling allowing the sales.

The brief order permitted two-pill versions of emergency contraception to immediately be sold without restrictions, but the court refused to allow unrestricted sales of the Plan B One-Step contraceptive until it decides the merits of the government's appeal. It did not specify why the two-pill versions were being allowed now, though it said the government failed to meet the requirements necessary to block the lower-court decision.

Plan B One-Step is the newer version of emergency contraception — the same drug, but combined into one pill instead of two.

The decision was met with praise from advocates for girls' and women's rights and scorn from social conservatives and other opponents, who argue the drug's availability takes away the rights of parents of girls who could get it without their permission. It is the latest in a series of rulings in a complex back-and-forth over access to the drug.

Shares of Teva Pharmaceutical Industries, which makes Plan B One-Step, increased 41 cents to $38.44 by midday. Shares of Perrigo Co., which has a two-pill pack, jumped nearly 3 percent to $116.47. And Actavis Inc. shares increased 44 cents to $120.78 amid a drop in the broader market.