* Calls the premature filing ``deeply regrettable''
* Third-quarter revenue misses analysts' estimates
* Cuts full-year revenue outlook
* Shares down 2 pct
(Adds background, conference call details, share movement)
Nov 1 (Reuters) - Printing services provider RR Donnelley & Sons Co, which mistakenly filed Google Inc's earnings report ahead of schedule two weeks ago, said it has put measures in place to prevent any such incidents in the future.
The company, whose third-quarter revenue fell more than expected, is the top agent for handling Securities and Exchange Commission filings and owns the EDGAR Online portal for SEC filings, used by corporations, analysts and investors.
Chief Executive Thomas Quinlan, on a conference call with analysts, called the incident ``deeply regrettable''.
``Everyone at RR Donnelley wishes it could have been undone ... We have already begun to implement additional enhancements that will help to prevent an extremely rare incident like this one from happening again,'' he said.
Filing agents such as Donnelley take paper documents and convert them for submission to the SEC in the appropriate format. As of mid-October, the company had handled more than 75,000 submissions this year, according to SECInfo.com.
RR Donnelley also lowered its full-year revenue forecast to $10.1 billion-$10.2 billion from $10.4 billion-$10.5 billion.
It also said full-year adjusted earnings are likely to be at the lower end of its forecast of $1.84 to $1.92 per share.
For the second-quarter, net income fell to $71.4 million, or 39 cents per share, compared with $158 million, or 83 cents per share, a year earlier.
Excluding items, it earned 51 cents a share, above the 44 cents analysts were expecting.
Revenue fell about 7 percent to $2.51 billion, missing the analysts' average estimate of $2.58 billion.
Net sales for its U.S. Print and Related Services unit fell 6.4 percent to $1.9 billion.
Shares of the Chicago-based company were down 2 percent at $9.78 in early morning trade on the Nasdaq on Thursday.
(Reporting By Aurindom Mukherjee in Bangalore; Editing by Sreejiraj Eluvangal)