West Lafayette-based Bioanalytical Systems Inc. has promoted Anthony S. Chilton to CEO following the retirement of top executive Richard M. Shepperd earlier this year.

Chilton, the contract research firm’s chief operating officer, has been interim president since his predecessor stepped down in January. The 53-year-old also got that job on a permanent basis.

The company announced Chilton’s appointment Thursday, citing his 30-plus years of experience as a scientist and executive at life sciences enterprises in England, Canada and the United States.

Located in Purdue University’s Research Park, Bioanalytical Systems was founded in 1974 by Pete and Candace Kissinger. Over the years, it grew into one of Indiana’s largest life science firms. The couple led the company until August 2007, when they stepped down from their management posts. He had been CEO; she was vice president of research. The Kissingers remain Bioanalytical Systems’ largest shareholders, with a 26-percent stake.

Bioanalytical Systems hired Shepperd to cut costs, and he ended up presiding over one of the roughest patches in the firm’s history. Annual revenue declined from $45.2 million in 2007 to $31.8 million in 2009. And the modest $926,000 Bioanalytical Systems booked as profit in 2007 was followed by two years of losses: $1.5 million in 2008 and $5.5 million in 2009.

It reported a $1.4 million first-quarter loss this year.

As a result, Bioanalytical Systems’ stock price has tumbled. Before the recession began, the company’s shares traded on NASDAQ for more than $8 each. The stock closed at $1.10 on Thursday.

At its peak, Bioanalytical Systems had 375 employees. According to the firm's 2009 annual report, headcount had shrunk to 257.