Banco Espírito Santo said Friday it believes any losses related to its exposure to its parent group are fully covered by capital buffers, the latest attempt to reassure jittery markets about the possible fallout from a series of financial entanglements.

BES, as the troubled Portuguese lender is known, said it is also committed not to increase its total exposure to the Portuguese conglomerate that controls the bank through the firm Espírito Santo Financial Group SA, or ESFG.

Shares in both BES and BSFG have been suspended from trading since Thursday, following steep losses on reports of accounting irregularities throughout the conglomerate, as well as delayed coupon payments to some short-term securities.

In its statement Friday, BES provided some details about its exposure to the conglomerate, which it said tallies EUR1.18 billion ($1.61 billion) through loans and securities, on which it has guarantees of just EUR56.9 million.

BES added that its capital buffer is above the minimum regulatory level for European banks.

In addition to BES's direct exposure, the bank said its retail clients hold EUR853 million in commercial paper issued by four companies that are part of the conglomerate. BES also said it had under custody just over EUR2 billion worth of Espirito Santo Group debt on behalf of institutional investors.

BEs" woes have led to a worsened mood in global markets, particularly regarding Portuguese assets. Just Friday, Portuguese construction firm Mota-Engil SGPS SA said it is delaying a planned initial public offering for its African unit, citing deteriorated market conditions.

Christopher Bjork in Madrid contributed to this article