Applying CoS during a pending app with another category

[malatian]

Hi everyone! I've got a weird situation and would be grateful if anyone can help me with my question..

I've been working for my current employer since 9 Jan 2012. Upon completing 1 year of employment, on 9 Jan 2013, I have applied ECAA 1 Turkish Employed Visa. My passport is still with UKBA and my previous visa expired on 19 Jan 2013. Average waiting time for ECAA 1 applications is 5 months, therefore I don't expect my current application to be decisioned earlier than June.

Now the tricky part... I have received a job offer from another firm which I would like to accept as soon as possible. They are alright with sponsoring and have completed RLMT but my passport is with UKBA. What I'd like to know is, is it possible to apply CoS without withdrawing my current ECAA1 application?

The reason why I'm asking this is that I'd like to be fairly confident (have my CoS ready) before withdrawing my current application, as I will need to make my Tier 2 application from Turkey.

Thanks so much already ^^