In order to fly for an airline you are likely to need a multi-pilot airplane type rating,and according to JAR-FCL1.250 there are 4
pre-requisite conditions to complete a MPA type rating:
1.have at least 100 hours as pilot-in-command of airplanes.
2.have a valid multi-engine instrument rating
3.hold a MCC certificate
4.have JAA ATPL theory
Having said that, it looks like you are missing the last two conditions and I can not see how you can log hours on a multi-pilot airplane without a type rating.