By Mathieu Rosemain and Gwénaëlle Barzic

PARIS (Reuters) - Vincent Bollore's recent judicial and health woes laid the ground for the handover of his business empire to his four children, the French tycoon has written in a first-hand contribution to a business book.

Excerpts from 'Dictionnaire amoureux de l'entreprise et des entrepreneurs' - The Dictionary for Lovers of Business and Enterprise - were published by Challenges magazine on Thursday.

It is the first time Bollore, a secretive and influential tycoon who built a media-to-logistics group worth 15 billion euros over a forty-year career, has publicly mentioned a medical condition as a reason for taking a step back.

He didn't elaborate further. A spokesperson for Bollore declined to comment on the nature of the health issues.

"The anticipation (of the company's handover) was facilitated by a string of difficulties that concerned me: judicial, medical and in the running of the business, which could be signs that the end of my time was coming and that it was necessary to hand over," Bollore wrote.

The 69-year-old businessman has long said he would give up the reins of his eponymous company, which controls media and publishing group Vivendi, before next month's 200th anniversary of the family-run group.

A recent decision to sell his African logistics assets, which Bollore spent a lifetime building up, shows a willingness to swiftly withdraw from the group's historical activities and make Vivendi and its myriad of holdings, including in phone company Telecom Italia, the group's new centre of gravity.

The decision came after probes into allegations of corruption on the continent.

While his group put an end to the case by agreeing to pay a 12 million-euro fine last year, Bollore remains under formal investigation in France over the allegations that his company bribed public officials in Togo, a spokesperson for the French prosecutor said.

Bollore said he had already shifted ownership of his controlling stakes in the company to his children. But he still controls the voting rights tied to the shares, a spokesperson for the group said.

(Reporting by Mathieu Rosemain; Editing by Kirsten Donovan)