Engine issues for Marussia
Marussia are chasing a new engine partner for 2014 with Cosworth due to withdraw at the end of the current campaign.
After a four-year absence from Formula One, Cosworth returned at the start of 2010 when the sport welcomed three new teams in Virgin Racing (now Marussia), Lotus F1 Team (now Caterham) and HRT.
Cosworth supplied the trio, along with Williams who also signed up with the Northampton-based company.
Lotus, however, switched to Renault from 2011, as did Williams from the start of last year, and with HRT now defunct, it leaves Marussia as Cosworth's only customer.
With the engine regulations due to change from next year, with teams running 1.6-litre turbo-charged V6 powerplants instead of 2.4-litre V8s, it would not be financially prudent for Cosworth to continue.
Marussia sporting director Graeme Lowdon said: "My understanding is Cosworth won't be making a 2014 engine.
"Obviously I don't work for Cosworth, but that is my understanding. The three suppliers will be Mercedes, Renault and Ferrari."
With Renault already supplying four teams in Red Bull Racing - Lotus, Williams and Caterham - they are unlikely to be willing to stretch their resources to a fifth team.
Should that status quo remain, it means Banbury-based marque Marussia will have to choose between Mercedes and Ferrari.