By Maki Shiraki, Daniel Leussink and Norihiko Shirouzu TOKYO (Reuters) - Japan's Nissan will unveil a shake-up in its top ranks next month, three people familiar with the matter said on Thursday, adding that embattled CEO Makoto Uchida is currently expected to hang on to his job.

Nissan faces mounting financial pressures, with a record debt bill coming due next year. It has also been struggling to attract consumers with an ageing vehicle lineup and has relied heavily on incent