(Adds Perrigo lawsuit against Mylan, closing stock prices)
By Caroline Humer
Sept 17 (Reuters) - Generic and over-the-counter drugmaker Perrigo Co on Thursday urged its shareholders to reject Mylan NV's unsolicited $27 billion tender offer, saying it substantially undervalued the company.
Mylan first proposed to buy Perrigo in April and, after being repeatedly rebuffed, launched a tender offer on Monday.
It has said it would take control if more than 50 percent of Perrigo shares are tendered in the offer. That strategy is possible under takeover law in Ireland, where Perrigo has been incorporated since buying Irish drugmaker Elan in 2013.
Perrigo also filed a lawsuit against Mylan in Manhattan federal court, seeking an injunction to block the closing of any tender offer unless Mylan corrects its alleged misleading statements to Perrigo shareholders about a potential merger.
The lawsuit said Mylan overstated potential synergies, and falsely claimed power to delist Perrigo shares in an effort to strong-arm Perrigo shareholders into accepting the tender offer.
Mylan, in a statement, said the lawsuit had no merit and was "an attempt by Perrigo to further frustrate the tender process and to prevent their shareholders from tendering to Mylan in support of this compelling, value creating transaction."
Netherlands-based Mylan has offered $75 in cash and 2.3 of its shares for each Perrigo share, a combination now worth $188.55 based on Mylan's Thursday closing price of $49.37. Perrigo shares closed down $1.31 at $181.08.
Joseph Papa, Perrigo's chief executive, said in an interview that he does not believe his company's shareholders will agree to swap their shares for Mylan shares, and that the deal premium of 13 percent was lower than in other pharmaceutical takeovers.
"I canceled vacations this summer and I plan to spend more times with shareholders over the next 60 or so days to make sure they understand this is a bad deal," Papa said.
Perrigo shareholders have until Nov. 13 to take part in the tender offer.
Shareholders often wait until near the closing date before deciding to participate, so it is unclear if Mylan will succeed.
Buying Perrigo would give Mylan over-the-counter consumer and nutritional products and a line of generic topical medicines.
A takeover would be the latest in a string of recent multibillion-dollar pharmaceutical deals, including Valeant Pharmaceuticals International Ltd's $11 billion acquisition of Salix Pharmaceuticals Ltd and AbbVie Inc's $21 billion offer for Pharmacyclics Inc.
(Additional reporting by Jonathan Stempel in New York and Amrutha Penumudi in Bengaluru; Editing by Meredith Mazzilli and Grant McCool)