UPDATE 1-Bastos resigns as head of Brazil's BNDES as scandal heightens pressure

pressure@ (Adds government source, Temer comments and context)

RIO DE JANEIRO/BRASILIA, May 26 (Reuters) - Maria Silvia Bastos resigned on Friday as head of Brazil's massive development bank BNDES, the first senior official to leave the administration since a political crisis engulfed the government of President Michel Temer.

Bastos cited "personal reasons" for her resignation from the country's largest source of long-term corporate credit, the bank said in a statement, and will be replaced on an interim basis by director Ricardo Ramos.

Since her appointment last year she has been criticized by businessmen starved of subsidized loans amid the country's worst recession ever. Bastos, 59, had imposed tougher terms for loan disbursements and asked BNDES-appointed board members to tighten scrutiny of decisions at major companies.

A senior government official denied her departure was politically motivated and said Bastos fell from her spot because she had "lost command of the bank and employees did not accept her leadership."

The source, who spoke on condition of anonymity as he was not authorized to discuss the matter, said BNDES employees accused her of not defending their interests.

Bastos had opened a series of investigations into multi-billion dollar loans to major companies targeted by authorities for paying bribes to scores of politicians.

Temer, who is resisting calls for his resignation after allegations of corruption, commended Bastos for her job at the bank.

During her year at the helm of the bank she tightened the grip on once plentiful government-sponsored loans in 13 years of leftist Workers Party administrations.

Bastos turned against the bank's policy of handpicking a select group of firms, known as "national champions," to spearhead economic development.

Several of those investments turned sour, while some have come under federal investigation as part of a wider probe into bribery scheme at state-run enterprises.

BNDES has been ensnared in recent months in a mounting political scandal over investments in JBS SA, the world's largest meatpacker, years before Bastos took over at the helm of the bank. (Writing by Alonso Soto; Editing by Frances Kerry and Lisa Shumaker)