* Swiss expected to sign 12th tax deal on Thursday
* Will meet criteria for removal from tax haven list
* G20 to assess progress by offshore centres
* OECD already endorsed Swiss efforts
* Swiss still facing referendum on tax treaties
(Adds comments from Swiss Finance Minister, details)
By Lisa Jucca
ZURICH, Sept 24 (Reuters) - Switzerland is rushing to sign an additional tax information deal to secure its removal from a tax haven list later on Thursday, when a meeting of the Group of 20 nations starts.
Berne is planning to sign a 12th double-taxation treaty later today, fulfilling conditions for being be taken off the international tax haven "grey list" drafted by the Organisation of Economic Cooperation and Development (OECD), a Swiss diplomatic source told Reuters.
Swiss Finance Minister Hans-Rudolf Merz, who is in New York for the U.N General Assembly meeting, will take this opportunity to meet with the Emir of Qatar to sign the much-needed new tax treaty, Swiss Television said.
"With this, we would have the "grey list" behind"," Merz told Swiss television.
Merz is due to hold a press conference in New York at 1630 GMT.
G20 leaders agreed in April to name and shame offshore centres that did not cooperate on tax evasion and threatened them with sanctions.
That caused political embarrassment for Switzerland and other international offshore centres, which swiftly agreed to relax their bank secrecy rules.
The pressure was particularly high on Switzerland, the biggest offshore centre which manages one third of the world's wealth, at a time when banking giant UBS was facing a tax fraud probe in the United States.
Fear of sanctions pushed Berne to agree for the first time it would share with foreign tax authorities certain bank data on tax evasion matter, a move the local press described at the time as a capitulation.
But this time around Switzerland could take home a political victory if it manages to be removed from the OECD list.
STEP FORWARD
The G20 is expected to take stock of progress by offshore centres at its summit on Thursday and Friday in Pittsburgh.
Many offshore centres, including European Union members Austria and Luxembourg, have already been taken off the 'grey list' in recent weeks, putting pressure on Swiss authorities to act.
The list comprises countries that have not fully implemented global taxation standards.
Switzerland signed an 11th tax treaty with the United States on Wednesday. Signing the new treaty would allow Switzerland to be removed from the list.
"We would not stop here," Merz told Swiss television. "We will try to do more. We will continue to sign tax treaties with significant jurisdictions."
The Swiss, UBS and the U.S. government settled their tax case last month, with the bank agreeing to turn over 4,450 names of clients with undeclared accounts to authorities.
The OECD already signalled on Wednesday that Switzerland will soon be taken off the grey list.
"Signing agreements is only one step in a process. What we will now be looking for is effective implementation by all countries," OECD Secretary General Angel Gurria, attending a G20 summit that starts in Pittsburgh on Thursday, said in a statement.
But Switzerland still faces a potential domestic headache as one of the treaties will have to be put to a popular vote in a referendum.