July 15 (Reuters) - BayWa shares plunged in early trading ahead of the 0700 GMT official market open on Monday after it commissioned an external probe whether it can restructure its finances late on Friday. Shares in the Germany agricultural trading group dropped to the bottom of the German small-caps index, down almost 40% in early Frankfurt trade.

The Munich-based company, which has been grappling with rising borrowing costs, mentioned a "tense financing situation", saying it saw itself as a case for restructuring.

According to the quarterly report, the group had long-term bank debts of 3.1 billion euros at the end of March, plus short-term liabilities of almost 2.5 billion.

Last year BayWa said, it was planning to sale its struggling solar business.

The European renewable energy sector is under pressure from overcapacity in solar modules and from low-price Chinese competitors.

A restructuring report is usually required by creditors and is the prerequisite for them to grant further loans or to extend them.

(Reporting by Anastasiia Kozlova and Amir Orusov Editing by Ludwig Burger )