FRANKLIN, Tenn. - Community Health Systems Inc. is taking its $3 billion cash and stock offer for rival hospital operator Tenet Healthcare Corp. public, in a move to rally shareholder support for the deal.

Tenet shares surged nearly 50 percent in after-hours trading, rising $2.11, to $6.40.

Tenet and Community own hospitals in the Philadelphia area. Tenet has two hospitals in the city: Hahnemann University Hospital and St. Christopher's Hospital for Children. Community owns Chestnut Hill Hospital in Philadelphia and four suburban facilities: Brandywine Hospital, Jennersville Regional Hospital, Phoenixville Hospital, and Pottstown Memorial Medical Center.

Community Health said Thursday that it sent a letter to Tenet's board last month offering $6 a share for the Dallas company - $5 in cash and $1 in stock - which would represent a 40 percent premium to Tenet's closing price Thursday of $4.29.

Including assumed debt, the company values the deal at about $7.3 billion. Based on Tenet's 485.5 million shares outstanding Nov. 2, the cash and stock portion would be worth $2.91 billion.

Community Health said the cash portion would be funded with available cash on hand and debt financing.

Community Health, of Franklin, Tenn., says Tenet Healthcare's board rejected the offer Monday, saying it does not offer "even remotely fair value" to shareholders. Messages left for a Tenet spokesman were not immediately returned.

A combined company would have about $22 billion in annual revenue and own or operate more than 170 hospitals in 30 states.

Tenet Healthcare, which operates about 50 hospitals, last month reported a return to third-quarter profit as it booked hefty deferred tax benefits.

Revenue remained flat at $2.26 billion. Community Health, which operates more than 120 hospitals, in October reported quarterly earnings of $70.4 million on revenue of $3.25 billion.

Inquirer staff writer Stacey Burling contributed to this article.