Just a few months after closing its $67 billion acquisition of Wyeth Pharmaceuticals, Pfizer Inc. stands ready today to spend another $4 billion or so for Germany’s second-leading maker of generic medications, according to news reports.

The New York-based Pfizer and Israeli generics maker Teva Pharmaceutical Industries Ltd. are bidding for Germany’s Ratiopharm in a battle that pits the largest drug firm in the world against the leading provider of off-patent medications, according to the German business newspaper Handelsblatt.

The newspaper said another firm, the Swedish private-equity company EQT, also had been bidding, but appeared unlikely to prevail over Pfizer and Teva, according to a Reuters news service report today. Dow Jones Newswires reported last week that Actavis Group of Iceland also was interested in Ratiopharm, one of the world’s top five suppliers of generic medicines.

“Both would be buyers are emblematic of the shifting landscape,” said The Wall Street Journal Health Blog. “Pfizer ... has been moving away from the blockbuster-drug model and towards a more diversified business that includes a growing generics unit. Teva ... gets about 30 percent of its revenues from branded drugs, and has a market cap of more than $50 billion (higher than Eli Lilly’s) and ambitious growth plans.”

The increasing competitiveness of the two companies had been revealed again late last week when Pfizer asked a U.S. federal court in Delaware to block Teva from selling a generic form of the antibiotic Zyvox. Pfizer cited patent infringement in its suit, which sought an injunction against Teva and said Zyvox was protected from generic competition until at least 2014, according to Reuters.

Pfizer, with major research-and-development campuses in Groton and New London, has been diversifying its portolio of medicines in recent months. Earlier this year, it announced a deal to sell 40 generic drugs manufactured by Strides Arcolab of India, and last year Pfizer entered into similar agreements with the Indian generics firms Aurobindo Pharma Ltd. and Claris Lifesciences Ltd.

Pfizer does not comment about reported deals it is contemplating.

Teva said earlier this year that it expects to double its revenues in the next five years. Teva had been expected, along with France’s Sanofi-Aventis, to be among the most active suitors for Ratiopharm.

In 2004, when Pfizer had a different business model, it ironically sold to Teva its generics marketing company called Dorom, then one of the two largest suppliers of off-patent medicines in Italy.