* Nominee expected to win full Senate confirmation
* White House set to name deputy trade representative
* Kirk, wife paid $7,785 in back taxes this month (Adds Senator Grassley statement)
By Doug Palmer
WASHINGTON, March 12 (Reuters) - The Senate Finance Committee voted on Thursday to back the nomination of former Dallas Mayor Ron Kirk to be U.S. trade representative.
The panel's voice vote sets the stage for full Senate consideration. Senate approval would fill one of the last empty slots in President Barack Obama's Cabinet.
Meanwhile, the White House announced Obama plans to nominate Demetrios Marantis, a senior Senate Finance Committee aide, to be one of Kirk's deputy trade representatives.
Marantis worked for the USTR general counsel's office from 1998 to 2002 and then for the U.S.-Vietnam Trade Council before joining Democratic Senator John Kerry's 2004 presidential campaign as a key adviser. He has been with the Finance Committee since February 2005.
Kirk is expected to win Senate confirmation, even though the Finance Committee's vetting process revealed errors in his tax returns for 2005 through 2007.
Those included failing to report as income some speaking fees he donated to his college alma mater. He also overstated business-related entertainment expenses he took for Dallas Mavericks basketball tickets.
"This is not because he was purposefully trying to avoid taxes," Senator Charles Grassley, the finance panel's top Republican, said in a statement defending the committee's scrutiny of nominee tax returns.
"Each of the issues for which he amended his returns was considered by him and his preparer at the time the returns were prepared. However, upon further review of some of the calculations, he agreed that some of them needed to be changed," Grassley said.
TWO PAYMENTS
In written responses to questions from the Senate Finance Committee, Kirk said he and his wife paid $7,785 in back taxes in early March to clear up the matter.
That was on top of a payment of $2,327 in October 2008, after the Internal Revenue Service first discovered the error involving the speaking fees.
Several Obama nominees under the jurisdiction of the Senate Finance Committee have stumbled because of tax issues, most notably former Senator Tom Daschle. He withdrew as Obama's choice for health secretary after it was revealed he owed around $140,000 in back taxes.
U.S. Treasury Secretary Timothy Geithner was found to owe $48,268 in back taxes but won confirmation.
Kirk, a friend of Obama, was the first black mayor of Dallas from 1995 to 2001, when he stepped down to launch an unsuccessful Senate bid. Since then, he has worked for a law firm in Dallas and was active last year in Obama's campaign.
Kirk told the Senate Finance Committee during his confirmation hearing on Monday that he would push to make sure that other countries live by the commitments they have made in international trade pacts.
He put less emphasis on negotiating new agreements.
"As I've said to many of you in private, I don't come to this job with deal fever, and we're not going to do deals just for the sake of doing some," Kirk said.
Obama also is still waiting for his commerce secretary nominee, former Washington Governor Gary Locke, to be approved.
Senate Commerce Committee Chairman Jay Rockefeller told Reuters the panel was waiting for more paperwork on Locke before scheduling a hearing. (Additional reporting by Jeremy Pelofsky; Editing by Xavier Briand)