The pharmaceutical industry was abuzz Monday after Pfizer publicly announced its interest in pursuing what would be the largest pharma deal ever: a potential $98.7 billion acquisition of the U.K.’s AstraZeneca.

Pfizer confirmed Monday that it held discussions with AstraZeneca in early January concerning a potential mega-deal that would value the British company at $76.62 per share—a 30 percent premium over AstraZeneca’s share price at the time of the talks. AstraZeneca said Monday that its board rejected that offer, which it felt “very significantly undervalued” the company.

In a statement released Monday, AstraZeneca’s board asked the company’s shareholders not to take any action regarding Pfizer’s announcement and remained adamant that no deal was in place between the two companies. Pfizer’s announcement lauded a combination it says would result in an “industry-leading” portfolio of cancer drugs, including treatments for lung and breast cancers.

Should Pfizer manage to reach an agreement with the rival drug company, the resulting transaction would surpass a previous Pfizer deal for the largest-ever pharmaceutical purchase. In 2000, Pfizer paid roughly $90 billion for the Warner-Lambert Company.

Skadden, Arps, Slate, Meagher & Flom is advising Pfizer on its proposed acquisition with a team led by corporate partners Michael Hatchard and Scott Hopkins in London, while corporate partners Paul Schnell, Sean Doyle and Michael Chitwood are leading the firm’s U.S. team. Tax partners Tim Sanders and Sally Thurston are also advising along with competition partner Sharis Pozen and associates Grace Fu and Adam Howard.

Skadden’s previous work for Pfizer includes representing the company on the spinoff of its animal health business Zoetis, followed by a $2.6 billion initial public offering for the standalone company last year.

For its part, AstraZeneca is represented by attorneys at Davis Polk & Wardwell and Freshfields Bruckhaus Deringer. New York-based corporate partner Paul Kingsley is leading the way for Davis Polk, which advised AstraZeneca in December on a $3.4 billion investment in the company’s diabetes joint venture with Bristol-Myers Squibb. A Freshfields spokesman did not immediately respond to The Am Law Daily’s request for information regarding the firm’s deal team.