Drugmaker Mylan's merger with Pfizer off-patent branded drug unit, Upjohn, will now close in the second half of this year, the companies said tody.

The two companies blamed the coronavirus pandemic for the delay. 

Due to restrictions on large gatherings, the general meeting of shareholders to approve certain matters for the deal to go through has been postponed to June 30, Mylan said. 

There were no other changes to previously announced terms or plans pertaining to the deal, previously expected to close in mid-2020, the companies said. 

The merger will bring blockbuster treatments Viagra and Lipitor from Pfizer under one umbrella with Mylan's EpiPen.

The deal is part of years-long effort by Pfizer to split into three parts - innovative medicines, lower margin off-patent drugs facing generic competition and consumer healthcare. 

The combined company is expected to have 2020 revenue of $19 billion to $20 billion.