GlaxoSmithKline Plc's (GSK) antidepressant Paxil CR (search) has gone back on sale in the United States, following the resolution of problems at a manufacturing plant in Puerto Rico, the British-based group said on Monday.

Supplies of diabetes medicine Avandamet, which is made at the same factory, are expected to resume within two weeks, it added in a statement.

U.S. regulators seized shipments of both drugs in March because of quality problems at the Cidra site, which resulted in some tablets splitting or containing incorrect doses.

Europe's biggest drugmaker had said two months ago that it expected to get the two withdrawn products back on the U.S. market by mid-year after signing a legal agreement with the Food and Drug Administration (search) to put right the deficiencies at Cidra.

Supplies will return to other markets shortly after.

The early return of the drugs is a relief to investors who had feared problems at Cidra could jeopardise earnings.

A company spokesman reiterated on Monday that the group remained on track to increase earnings at a low double-digit percentage rate in 2005, when measured at constant currencies.

Annual U.S. sales of the two products totalled around $1 billion before the suspension, with Paxil CR alone selling some $700 million in 2004.

GSK was allowed to continue making medicines at the Puerto Rico plant and the FDA said at the time of the suspensions that the manufacturing issues were not a significant risk for patients.

Paxil CR is a controled-release version of GSK's original Paxil antidepressant, which has now lost patent protection.

British drug delivery specialist SkyePharma Plc (search) developed the controled-release technology used to make the tablet and receives a percentage of Paxil CR sales.

Industry analysts said some investors were cautious ahead of a vaccines seminar on Thursday which could be anticlimactic, particularly as GSK may not yet be ready to announce a U.S. filing date for Cervarix, its cervical cancer vaccine.

Sandford Bernstein analyst Gbola Amusa also dampened enthusiasm about the broader new drug pipeline at GSK, arguing in a note that most of the mid-stage clinical trial results the company had highlighted for 2005 were too early to move the stock price.