Southwest Airlines, the $15.6 billion Dallas-based air carrier, promoted Chris Monroe to treasurer. He succeeds Scott Topping, who left in October 2011 to become CFO and executive vice president at Hawaiian Airlines. Monroe was named assistant treasurer in 2011 and also served as financial analyst, director of ground operations planning and financial planning controller since joining the company in 1991.

LPL Financial, a $3.4 billion Boston brokerage, appointed Dan Arnold CFO, effective June 15. He succeeds Robert Moore, 50, who was named president and COO. Arnold, 47, previously was head of strategy for LPL, the largest independent brokerage in the U.S. He also served as president of Institution Services, a company LPL acquired five years ago that provides banks and credit unions with investment and insurance services

Hubbell, a $2.8 billion electrical and electronic product manufacturer, named William R. Sperry CFO and senior vice president. He succeeds David G. Nord, 54, who was named president and CEO of the Shelton, Conn., company. Sperry, 50, has been Hubbell's vice president of corporate strategy and development since 2008. He has previously served as a managing director at Lehman Brothers and worked at J.P. Morgan and McKinsey & Co.