NEW YORK (AP) — Elan Corp. said Tuesday its board of directors engaged Citigroup Global Markets as part of a review for strategic options that could include a sale of the company. The Ireland-based biotechnology company is in the midst of restructuring some operations and has been dealing with some shareholder anger. In December, the company said it is closing its offices in New York and Tokyo during the first quarter and it will eliminate an unspecified number of positions while revising marketing activities for Tysabri as a drug for Crohn’s disease, an inflammation of the digestive tract. Elan and partner Biogen Idec Inc. reported four cases of the brain infection PML in Tysabri multiple sclerosis patients during 2008. The drug had been pulled from the market in 2005 after being linked to PML, then reintroduced under restricted sales conditions in mid-2006. In a letter to the board in December, investor CrabTree Partners called for the removal of Chief Executive Kelly Martin and other key changes, saying the company’s performance was unacceptable. American Depository Shares fell 72 percent in 2008. The company still faces a a class-action lawsuit by the firm Barroway Topaz Kessler Meltzer & Check LLP in U.S. District Court for the Southern District of New York. In a statement Tuesday, the company said it is committed to completing a review of potential alternatives “as promptly as practicable.” “Given our many scientific, clinical and commercial opportunities and the capabilities of the industry participants that surround us, the board of directors has determined that this is an appropriate time for the board to explore potential alternative paths forward for the Company,” said Chairman Kyran McLaughlin, in a statement.