On Assignment Inc. has entered into a letter of intent to buy a clinical research staffing firm, which operates in Western Europe, for $17 million.

The Calabasas health care and scientific staffing company on Wednesday said that its acquisition is projected to produce annual revenue of about $24 million. The deal is expected to close in the next 45 days.

“This company has margins that are consistent with our life science staffing business, long term assignments and high bill rates; it should be nicely accretive to our earnings,” said Chief Executive Peter Dameris in a statement.

On Assignment now has 70 staffing branch offices in the United States, United Kingdom, Netherlands, Ireland and Belgium, and provides physicians in Australia and New Zealand.

Shares were down 14 cents, or 1.6 percent, to $8.51 in midday trading on the Nasdaq.