Senior U.S. official visits Egypt as Islamists plan more
protests  * Senior U.S. official to visit Egypt, first since
overthrow  * Unclear if Burns will meet Mursi's Brotherhood
supporters  * New cabinet to be formed, more protests called  By
Shadia Nasralla and Ulf Laessing  CAIRO, July 15 (Reuters) - The
first senior U.S. official to visit Egypt since the army toppled
the country's elected president will hold high-level talks on
Monday in Cairo, where thousands of supporters of the ousted
Islamist leader are expected to take to the streets.  Egyptians
have been shocked by violent protests that have killed 92
people. However, despite deep divisions between those who
supported and those who opposed overthrown President Mohamed
Mursi, they are united by their suspicion of Washington's
motives.   Burns' visit, which will include talks with the
military, comes as Egypt's interim prime minister finalises his
cabinet.  It has been given the task of implementing a military-
backed plan to hold parliamentary election