LONDON, May 17 (Reuters) - The first phase of the new code of conduct aimed at participants in the $5 trillion-a-day global market in foreign exchange will be published on May 26, the Bank for International Settlements said in a statement on Tuesday.

Central bank officials working on the code had told Reuters previously the first document was on course to be published as promised in May.

The code is expected to lay out general principles for how banks, traders and investors should behave after three years during which banks have been fined millions for the manipulation of currencies by traders.

It is expected to be followed later by rules and possibly new regulation on the more thorny issue of how the code and its ideas are enforced.

(Reporting by Patrick Graham, editing by Nigel Stephenson) ((patrick.graham@thomsonreuters.com; +44 207 542 9429; Reuters Messaging: patrick.graham.thomsonreuters.com@reuters.net))