DOHA, Qatar  Qatar is buying shares in Credit Suisse and plans to spend as much as $15 billion on European and American bank stocks over the next year, according to its prime minister.

“We have a relation with Credit Suisse, and we bought some of the stock from the market, actually,” said Sheik Hamad bin Jassim al-Thani, who is also chief executive of the Qatar Investment Authority. “But I cannot say what percentage because still we are in the process.”

Qatar, which has a population of fewer than one million, holds 1.3 percent of global crude oil reserves.

Sovereign wealth funds in the gulf, whose coffers are swelling from high oil prices, as well as counterparts in Asia, have been snapping up stakes in banks battered by losses from subprime mortgages.