Alba said on Tuesday Mumtalakat will sell up to 163 million ordinary shares in the firm. An Alba spokesman said the company had 1.42 billion shares outstanding.

Mumtalakat owns 77 percent of Alba, with Saudi Basic Industries (SABIC) holding a minority stake.

Alba confirmed it had appointed JP Morgan as bookrunner and lead manager for the IPO. Bahrain-based Gulf International Bank (GIB) will act as regional lead manager and Citigroup as co-manager.

The ordinary shares would be listed on the Bahrain Stock Exchange while its global depository receipts would be listed on the London Stock Exchange, it said in a statement.

Alba Chairman Mahmood Hashim Al-Kooheji told Reuters last month the firm planned an IPO this year.

Mumtalakat, which bundles Bahrain's non-oil state-owned companies, is one of the smaller sovereign wealth funds in the world's top oil-exporting region, with $9.1 billion in assets at the end of 2009.

The fund, which also owns Bahrain's national carrier Gulf Air, plans to divest some of its local holdings and diversify its portfolio to more international and more liquid assets.

Alba, which operates an aluminum smelter in Bahrain, posted a full-year net loss of $220.7 million in 2009, compared with a profit of $781.9 million the year before, due to lower aluminum prices, according to a Mumtalakat investor presentation from June.