KANSAS CITY, MO. (

TheStreet

) --

H&R Block

(HRB) - Get Report

shares sank on huge trading volume Wednesday after the tax preparation services provider warned it would miss its 2010 earnings outlook as more customers seek to do their taxes without professional assistance.

Back in December, the company forecast a profit of $1.60-$1.80 a share for its fiscal 2010 year, which ends Apr. 30. But, as the official 2010 tax season picks up steam, the lingering recession and continued high unemployment have hurt revenue at the Kansas City, Mo.-based firm and its rivals, which depend on individuals and small businesses for business.

H&R Block said it's prepared 10.1 million tax returns year-to-date through Feb. 15, 6.3% fewer compared to the same period in 2009. Same-office tax returns fell 5.6% year-to-date through Feb. 15, it said.

Total retail returns prepared year-to-date fell 8.2% to 7 million, while the net average retail fee per tax return inched higher by 1.9% to $190.31, H&R Block said. In addition, H&R Block's online tax return services growth of 3.1% was "more than offset" by a 7.6% decline in its software-based tax return programs. Total digital returns fell 1.4%, the company said.

"We believe industry filings are down significantly due to the recession and sustained, high levels of unemployment," Russ Smyth, CEO and president of H&R Block, said in a statement on Wednesday. "The weak economic conditions have also contributed to a greater shift to do-it-yourself tax preparation methods among first-half clients. We still have millions of clients to serve in the second-half of the tax season, which we are aggressively targeting."

Shares were recently down $3.06, or 15.5%, to $16.67. Volume of 16.1 million was already more than five times the issue's trailing three-month daily average of 3 million.

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Jackson Hewitt Tax Services

(JTX)

, another tax preparation provider, also saw shares fall 4% to $2.38 on Wednesday.

A third rival,

Intuit

(INTU) - Get Report

, saw shares rise 1% on Wednesday to $32.18.

H&R Block is slated to report its third-quarter results after the closing bell on March 8. The current estimate of analysts polled by

Thomson Reuters

is for a profit of 16 cents a share on revenue of $959.2 million.

--Written by Laurie Kulikowski in New York.