Abbott Laboratories  (ABT) - Get Report  has finally gone public in an attempt to break free of its pending $7.9 billion cash-and-debt merger agreement with Alere (ALR) after months of sparring with the point-of-care testing company. 

The Abbott Park, Ill.-based buyer on Wednesday filed a suit against Alere in the Delaware Court of Chancery seeking to terminate the Feb. 1 transaction. With a string of issues having come to light over the past several months, Abbott is claiming that the Waltham, Mass.-based target has suffered from material adverse events, which as defined in their contract warrants its termination.

A redacted version of the sealed complaint is expected to be made public within three business days, Abbott spokesman Scott Stoffel told The Deal.

"Alere is no longer the company Abbott agreed to buy 10 months ago," Stoffel said in a statement. "These numerous negative developments are unprecedented and are not isolated incidents brought on by chance. We have attempted to secure details and information to assess these issues for months, and Alere has blocked every attempt. This damage to Alere's business can only be the result of a systemic failure of internal controls, which combined with the lack of transparency, led us to filing this complaint."

In response to Abbott's complaint, Alere issued a statement early afternoon on Wednesday asserting that the "lawsuit is entirely without merit."

"Alere has fully complied with its contractual obligations under the merger agreement and is highly confident that the merger will be completed in accordance with the terms set forth in the merger agreement," the statement said.

Abbott hasn't until now outright asked the court to let it walk from the deal it reached more than nine months ago, but the Miles White-led company arguably began to plant the seeds for a potential case months ago. Adding to the conjecture it wanted out in November, Abbott filed a breach of contract suit against Alere seeking further documentation and information as promised within their merger agreement. 

The merger agreement between Alere and Abbott contains language that allows either party to walk from the deal if the other suffers a material adverse effect, a term defined in the agreement itself. The Delaware law on MAEs is sparse, though the most important case interpreting an MAE was written in 2001 by Leo E. Strine., Jr., then a Vice Chancellor on the Court of Chancery and now the Chief Justice of the Delaware Supreme Court. Strine found that IBP Inc. had not suffered an MAE under its agreement to sell to chicken processor Tyson Foods Inc. and would not let Tyson walk from the deal.

Strine wrote in the case that an MAE clause "is best read as a backstop protecting the acquirer from the occurrence of unknown events that substantially threaten the overall earnings potential of the target in a durationally significant manner," since most merger agreements—including the one between Abbott and Alere—are heavily negotiated and contain numerous conditions that both parties must meet in order to close the deal.

In papers filed earlier in its litigation with Alere, Abbott has tried to point to other provisions of the merger agreement that the target has breached, which suggests the buyer will not rely solely on an MAE argument to walk from the deal. Those provisions include representations and warranties regarding the target's behavior before and after the deal was signed. 

Among issues raised include a March filing by Alere that disclosed it had received a criminal subpoena from the U.S. Dept. of Justice regarding issues relating to the U.S. Foreign Corrupt Practices Act (FCPA).

Abbott has also pointed to a U.S.  DOJ criminal subpoena the target received in July involving its toxicology business, as well as the Civil Investigative Demands from the U.S. Attorney's Office for the Middle District of Tennessee that Alere received in July related to an investigation of possible improper claims submitted to Medicare and Medicaid. 

Most recently, Alere on Nov. 4 disclosed that its diabetes unit Arriva lost Medicare enrollment. 

Hoping to force the buyer's hand, Alere was the first to sue Abbott on Aug. 26 in the Court of Chancery. Alere has contented that Abbott has dragged its feet in obtaining antitrust approval for their deal in an effort to kill the transaction, which has an April 30 drop-dead date. Abbott, for its part, has consistently said that is has acted in accordance with the merger agreement, blaming its postponement on the target's failure and delay to provide certain documentation and financial information. 

Mediation efforts between the two parties fell apart in September. Vice Chancellor Sam Glasscock III subsequently scheduled a preliminary injunction hearing on Alere's claims for Jan. 27, essentially implying he still wants the two parties to keep discussions open. 

Wednesday's suit comes several months after an initial failed attempt by Abbott to break up with Alere. The latter in April publicly revealed it had turned down a termination fee of between $30 million and $50 million offered by the buyer.  

Abbott shares retreated 1.3% to $37.92 Wednesday morning, while shares of Alere dropped less than 1% to $39.70. 

As the fate of the Alere deal grows increasingly uncertain, Abbott's $30.7 billion deal for St. Jude Medical  (STJ) , a maker of heart-failure devices and atrial fibrillation products, remains on track to close by the end of the year.