Aetna Inc. agreed to pay $5.7 billion in cash and stock for health insurer Coventry Health Care Inc. on August 20. The buyer will also assume $1.7 billion in Coventry debt, giving the deal a total value of $7.3 billion. The target’s shareholders will receive $27.30 in cash and 0.3885 Aetna shares per Coventry share, consideration worth $42.08, a 20 percent premium to Coventry’s closing price on August 17, the last trading day before the deal was announced. The deal would be the largest that Aetna has signed up since it completed a major reorganization in 2000 by selling its financial services and international businesses to ING Groep N.V. for $7.7 billion.

The acquisition would bolster Aetna’s ability to provide government-supported health care plans, and the market applauded the deal, bidding Aetna’s stock up by 4 percent on the news. WellPoint Inc. was motivated by the same goal in agreeing to buy managed care company Amerigroup Corporation for $4.9 billion in cash on July 9. Aetna and Coventry hope to close the deal by the middle of next year, pending approvals by regulators and Coventry shareholders.