Intertek will provide offshore chemists at three of the Danish oil giant's platforms as well as a supporting laboratory team.
They will conduct services such as gathering and testing samples and monitoring process systems to support Maersk's UK North Sea operations.
The three-year contract has the option for two one-year extensions. Raymond Pirie, vice-president of Intertek's global upstream business, said: "We are pleased to have secured the contract with Maersk Oil UK and look forward to supporting the company in its operations.
"Our provision of field services is complemented by in-house scientists who have access to advanced instrumentation to respond to complex analytical challenges.
"Intertek's laboratory supports the oil and gas value chain across its entirety, from reservoir to refinery."
FTSE-100-listed Intertek, which has hired Scottish Enterprise chief executive Lena Wilson as a non-executive director, said it has invested £4.5m in laboratories in its energy services hub.
First Minister Alex Salmond opened the Aberdeen headquarters of Intertek's energy services business in November.
More than 160 people are based there and Intertek predicts this number could rise to 220 over the next three years.
Intertek, which tests products from toys and clothes to oil and minerals, reported a 27% rise in profit for the first half of 2012 to £140m. Revenue increased by around 30% to £991m.