Hundreds of litres of fuel have leaked from the Altona Mobil refinery in Melbourne's west on Saturday.

Firefighters were called to the refinery at the corner of Millers and Kororoit Creek roads after the leak was detected about 11.30am.

Firefighters attended the Altona Mobil refinery after a fuel leak on Saturday. Credit:Pete Glenane/Hivis Pictures

MFB spokeswoman Heather Stockton said the spill was under control when firefighters arrived.

"We had reports of about 700 litres of product which had leaked from a petrol line that had corroded," she said.