Pfizer Inc. has approached Botox-maker Allergan PLC about a potential merger, the Wall Street Journal reported Wednesday, citing people familiar with the matter. The deal, if it materializes, would be one of the largest in the industry’s history -- topping Pfizer’s $116 billion acquisition of Warner-Lambert Co. in 2000.

However, according to the Journal, the process is still at an early stage and may not yield an agreement. Last year, Pfizer made a $120 billion takeover bid for the Anglo-Swedish pharmaceuticals group AstraZeneca PLC, before eventually withdrawing its proposal. 

An acquisition of the Ireland-based Allergan would create a company with a combined market value of nearly $330 billion. Allergan is the third-largest generic drugmaker in the U.S. following its merger in March with Actavis, for which Pfizer had made an unsuccessful takeover bid last year.

A transaction between Allergan and Pfizer might cap what is already a busy year insofar as pharmaceutical mergers are concerned. The first half of 2015 has witnessed over $200 billion surge in pharmaceutical deals. Additionally, a tie-up with Allergan could pave the way for the New York-based Pfizer to lower its corporate tax expenditure -- allowing it to relocate to Dublin, which has a significantly lower tax rate.

The deal would also help Pfizer boost its revenues. For the third quarter of 2015, the company reported $12.1 billion in revenue -- helped by its $16 billion deal to buy Hospira Inc. Allergan, which is yet to report earnings for the most recent quarter, posted a net revenue of $5.8 billion in the second quarter.

Stocks of both companies have performed well on the New York Stock Exchange this year. While Pfizer’s shares have risen nearly 13 percent year-to-date, Allergan has gained 10.6 percent.