NEW YORK (AP) -- Chemical company PolyOne Corp. reported an 11 percent increase in its third-quarter net income on Wednesday and disclosed it has agreed to buy plastics products maker Spartech Corp. for $246 million in stock and cash.

PolyOne makes resins used in plastic pipe and other products, and said the earnings increase reflected an improved product mix.

The deal for Spartech would give PolyOne a "leading market position in sheet, rigid barrier packaging and specialty cast acrylics," according to PolyOne Chairman and CEO Stephen D. Newlin. He said the combination will would enable PolyOne to "accelerate growth for both companies."

"We believe this is a very compelling transaction for our shareholders, customers and employees," Newlin said.

Vicki Holt, president and CEO of Spartech, based in St. Louis, noted in a statement that PolyOne and Spartech have "complementary growth strategies" and by combining sources, it expects to make advances in innovation and market access.

Under the terms of the deal, Spartech stockholders will receive $2.67 in cash and 0.3167 shares of PolyOne common stock for each share of Spartech common stock.

Based on the closing price of PolyOne shares Tuesday, Spartech stockholders will receive cash and stock valued at $8 per Spartech common share, a 56 percent premium over Spartech's closing price of $5.14 per share Tuesday.

The deal also includes the assumption of Spartech's net debt of $142 million.

In its earnings report, Cleveland-based PolyOne said that it earned $24.0 million, or 27 cents per share in the three-month period ended Sept. 30. That compares with $21.6 million, or 23 cents per share in the year-ago period.

Excluding unusual items, the company said its adjusted earnings came to 33 cents per share. That topped analysts' forecasts for earnings of 31 cents per share, according to FactSet.

Revenue rose to $740.2 million from $735.8 in the year ago period. Analysts expected revenue of $795.3 million.

Both companies' shares rose Wednesday. Shares of PolyOne rose $1.52, or 9 percent, to $18.36 per share, while Spartech's shares $3.24, or 63 percent, to $8.38.