UPDATE 2-Temple-Inland profit tops forecast, shares soar

* Q1 EPS 30 cents ex-items vs estimate 5 cents

* Company qualifies as alternative energy mixer

* Shares jump more than 30 pct to 6-month high (Adds details, alternative energy tax status, updates shares)

NEW YORK, April 22 (Reuters) - Corrugated packaging and building products maker Temple-Inland TIN.N posted quarterly earnings that easily beat expectations, helped by higher prices and lower costs, sending its shares up more than 30 percent.

It also said shipments in the current quarter were rising.

"After bottoming in September 2008, we have seen a slow but steady improvement in our box shipments," CEO Doyle R. Simons said on a conference call on Wednesday.

"To date, our April box shipments are up approximately 4 percent compared to March 2009."

Temple-Inland also said U.S. tax authorities in late March approved the company as an alternative fuel mixer, which qualifies it to claim a 50-cent per gallon tax credit for using biomass-generated fuel.

The company began using alternative fuels in late March at four plants, and expects to use 550 million to 650 million gallons on an annual basis, Simons said.

Net income for the first quarter was $35 million, or 33 cents per share, compared with a loss of $13 million, or 12 cents per share, a year earlier.

Excluding a one-time $6 million gain from debt retirement and a $2 million charge for plant closures and job cuts, earnings were 30 cents a share, well above the average analyst forecast of 5 cents a share and topping the highest analyst estimate for 12 cents a share, according to Reuters Estimates.

Revenue was little changed at $941 million. Analysts had expected $911.8 million.

In morning trading, Temple-Inland shares were up 28 percent at $9.29, their highest mark since October. The stock traded as high as $9.61. (Reporting by Hezron Selvi; editing by John Wallace and Ted Kerr)