Arab Banking Corp., Bahrain's largest offshore bank, said it was setting aside its entire 1989 profit of $132 million to cover potential loan losses. ABC, which is owned by the governments of Kuwait, Libya and Abu Dhabi, said Sunday the addition to its loan-loss reserve was needed to reassure investors because the bank is planning a $250-million share offering to boost its capital by 25 percent. Troubles with the bank's Latin American loan portfolio helped cause interest income to fall 14 percent to $327 million in 1989 from $380 million in 1988. The drop largely reflected non-payment of interest by Brazil and Argentina, said Abdullah Saudi, the bank's president and chief executive. The drop in interest income was offset in part by an increase in fees and commissions, which rose 30 percent to $179 million last year from $138 million in 1988. Operating profit before taxes, minority items and loan loss provisions fell to $184 million in 1989 from $239 million. Saudi said the addition to reserves would boost the bank's provisions for doubtful loans to about 40 percent of its loan portfolio. Saudi said the $250-million share issue planned for the first half of this year will be listed in the Bahrain, Kuwait and Luxembourg stock exchanges. Funds raised through the share issue will go in part toward the setting up of a new ABC European subsidiary, Saudi said. The new company, provisionally named ABC Europe, will take care of ABC branches in Paris, Milan and London. It is likely to be based in London. Saudi said he hoped the bank also would expand in the Arab world.