By Kevin Drawbaugh

WASHINGTON, May 17 (Reuters) – The Wall Street reform fight enters its final stages in the U.S. Senate this week with an overdue reckoning on three issues that cut to the heart of how, and for whom, the financial system works.

Although a final vote is expected within days on the White House’s top domestic priority, lawmakers have yet to settle disputes on regulating over-the-counter derivatives; curbing risky trading by banks; and the power of state authorities.

There will need to be resolution on these topics before the Senate can approve a massive Democratic bill designed to make the financial system less prone to crises like that of 2007-2009.

Analysts say that could occur as soon as Wednesday or Thursday. Delays could postpone full approval to next week, however.

Major votes on amendments looked unlikely on Monday or Tuesday, due to primary elections involving senators Blanche Lincoln and Arlen Specter, both Democrats. Party leaders were expected to avoid close votes on controversial measures while the two were away on the campaign trail.