Citigroup is on track to eliminate 300 sales-and-trading jobs globally in 2012, according to people briefed on the process. The cuts follow a 5% reduction in Citigroup’s securities-and-banking unit last year, a move that culled 900 jobs. The sales-and-trading business is part of the securities unit, which employs roughly 17,000 people…The current round of job cuts was set in motion before the ouster last month of Vikram Pandit, Citigroup’s chief executive, and John Havens, the president and chief operating officer, who also ran the investment bank, the people said. Both Mr. Pandit and his successor, Michael Corbat, have said that controlling expenses is a priority. “We will remain extraordinarily focused on our efficiency ratios and our overall expense levels,” Mr. Corbat told analysts on Oct. 16, the day he was named to succeed Mr. Pandit.