Wyeth said today it bought Thiakis Ltd., a private British biotechnology company, for $30 million.

Wyeth may make additional payments of up to $120 million for the acquisition if Thiakis achieves specific performance milestones.

Thiakis' lead product is an experimental drug designed to treat obesity by suppressing appetities. Obesity is estimated to affect 300 million people worldwide. The drug is in the initial stages of human testing.

The deal allows Wyeth to address needs in therapeutic areas such as metabolic disorders, said Mikael Dolstein, president of Wyeth Research.

Wyeth has corporate headquarters in Madison, N.J., with its pharmaceutical operation based in Collegeville.