CF Industries Holdings Inc. (CF), after more than a year of back and forth, Friday finally reached a deal to purchase Terra Industries Inc. (TRA) for $4.7 billion, forming one of the world's biggest nitrogen fertilizer makers.

Hours after Norway's Yara International ASA (YAR.OS, YARIY) said it wouldn't raise its own $4.1 billion bid for Terra, CF inked the deal it had been pushing since January 2009. CF had been continually rebuffed by a Terra board that said it wasn't for sale. After briefly leaving the fracas, saying another bid would be too pricey, CF came roaring back in the last month when Yara and Terra signed a friendly pact, saying if Terra were for sale it wanted to be the buyer.

CF Chairman and Chief Executive Stephen R. Wilson said the companies are looking forward, not back at the turbulent trials. The companies anticipate annual cost savings of about $135 million, the top end of the range CF said it expected back when it first made the offer. Wilson said it was still early in the process, but now that CF has friendly access to Terra's books, he did admit that figure could rise.

"What I would expect is once we put our teams together, once we start working together, we may find additional opportunities," Wilson said.

Terra holders will get $37.15 and 0.0953 share of CF for each share of Terra, valuing the stock at $46.74 based on Thursday's closing price. After the deal closes, CF said it will offer $1 billion in new equity to help fund the purchase.

The combined company would rank as the world's second-biggest nitrogen-based producer, behind Yara, according to CF presentations. Yara will get a $123 million break-up fee as a result of its deal with Terra falling through.

Friday also marked the withdrawal of the fourth company involved in the fray, as Agrium Inc. (AGU) said it was ending its own hostile attempt at buying CF.

Rising commodity prices have sparked a flurry of deals in the crop-nutrient sector in recent weeks, and Terra's focus on nitrogen-based products has kept it among the most attractive operators. Nitrogen has been garnering attention because of the ethanol market and the low prices of natural gas, which is a major component of nitrogen.

The companies said Friday that Terra's focus on industrial customers and CF's agricultural focus would make their combination formidable.

Wilson said it was too early to comment on the management structure of the combined company and he said he had no announcement about Terra Chief Executive Michael Bennett's role in the combined company.

"His whole adult life has been at Terra," Wilson said. "I know, because I know him well, that he cares deeply about Terra and he will help us to do what's best."

Standard & Poor's equity analyst Kevin Kirkeby said the finalization of the CF and Terra deal puts the industry focus back on fundamentals, which are improving over the dismal 2009 year.

-By David Benoit and Kevin Kingsbury; Dow Jones Newswires; 212-416-2458; david.benoit@dowjones.com