* Bill sets $800 million for security along Mexican border

* Lawmakers have to reconcile Senate and House versions

By Jeremy Pelofsky

WASHINGTON, July 9 (Reuters) - The Senate on Thursday approved a wide-ranging $42.9 billion measure to pay for improving U.S. border security, clamp down on illegal immigration and beef up cyber security in fiscal 2010.

The Senate voted 84-6 for the annual spending bill funding the Department of Homeland Security for the year starting Oct. 1, and now lawmakers must work out differences with a $42.6 billion version of the bill that passed the U.S. House of Representatives last month.

Debate over the bills offered insight into deep divisions over how to address illegal immigration into the United States, beef up security on the U.S. borders, and what to do with the estimated 12 million people in the country illegally.

The Senate measure provides $10.1 billion for customs and border protection, including $800 million for bolstering security along the U.S. border with Mexico, where drug and weapons trafficking has spiked and sparked growing concerns.

The legislation also includes almost $400 million for cyber security, a 27 percent increase over fiscal 2009, and comes as several U.S. government websites were attacked in the past few days by hackers.

The Senate agreed to several amendments, including one that would block the release of photographs of abuse of detainees by U.S. personnel. The American Civil Liberties Union has sued to make the photos public.