BP (BP), Transocean (RIG) Divorce Would be Costly

With a lot of stress on the business relationship between BP (NYSE:BP) and Transocean (NYSE:RIG), it could cost the two potentially hundreds of millions if the relationship falls apart.

Transocean owned the Deepwater Horizon drilling rig, operated by BP, which exploded and started the Gulf oil spill.

Even though the Gulf incident ended up costing Transocean about $137 million, they see a disintegrating relationship with BP as much more costly.

In a filing with the SEC, Transocean said BP accounted for about 10 percent of its overall $9.6 billion in revenue for 2010. Existing agreements are valued at almost three times that, coming to $2.9 billion.

In the filing Transocean called BP its "most significant customer," and the loss of business with BP would probably end up having a "material adverse effect" on the company.

It wasn't clear if this was a reference to BP wanting Transocean and others to pay for part of the damages associated with the oil spill, but it's a strong probability it is.

Transocean closed Monday at $84.63, gaining $1.83, or 2.21 percent. BP closed at $48.47, up $0.37, or 0.77 percent.