UPDATE 2-Portugal antitrust body searches banks
* Regulator suspects violation of competition rules
* Discloses no other detail
* Banking group surprised by scale of operation
* Banks have no comment (Updates with banking association statement)
LISBON, March 6 (Reuters) - Portugal's anti-trust authority AdC on Wednesday searched several banks on suspicion they violated competition rules by exchanging market-sensitive commercial information.
AdC gave no further detail and did not say which banks were searched.
None of the banks contacted by Reuters would comment.
The Portuguese Banking Association said it was "surprised by this action and its dimension," considering that the sector faces tough competition and is transparent about pricing.
It said it was told by member banks that the searches related to an offence that could lead to fines.
AdC said it would give no other details because the case was covered by judicial secrecy legislation.
Publico newspaper said 16 judges and 25 prosecutors were taking part in the raids.
Shares in Portugal's main listed banks - Millennium bcp , Banco Espirito Santo and Banco BPI - were not affected by the news and even eked out gains.
BES was up 1.6 percent, followed by BPI rising 0.6 percent while BCP was unchanged in afternoon trading. The main Lisbon stock index was up 0.11 percent.
Portugal's banks have been hit hard by the country's debt crisis.
Millennium, Banco BPI and Banif all made use of recapitalisation funds for banks made available under the country's 78-billion-euro bailout during the eurto zone crisis. (Reporting by Andrei Khalip and Axel Bugge; Editing by David Cowell)