US-based pharmaceutical major Pfizer reported mixed sales results as Lipitor and other medicines posted disappointing revenue, while its nutritional products unit produced more favourable results.

Cholesterol-busting drug Lipitor witnessed a 13% fall in revenue to $2.39bn, attributed to generic competition, and could face further reductions when patent protection expires in November this year.

In contrast, nutritional product sales rose 3% and sales of consumer products, including painkiller Advil, rose 12%.

However, the company is expected to divest one or more of its non-core units to promote the growth of new medicines, with its nutritionals business likely to fetch as much as $7bn.

New Pfizer chief executive Ian Read recently commented that it could take until early 2012 for the company to develop fully fledged plans on which units to sell, with proceeds likely to go towards the repurchase of company shares.

Since introducing Viagra in 1998, Pfizer laboratories has not produced a single best-selling medication, and the results of its non-core businesses have helped offset anaemic drug sales.