Consortium

Dear Sirs,

One indian public company, one partnership firm and one non resident (german) decided to accept a local authority's consultation work in india as a consortium. whether it is necessary to have a constitution for consortium? if yes, what?  they would like to dissolve the same after this venture. can it be formed as company , partnership firm, LLP or SPV ? what are the formalities ?

what is SPV & what are the formalities for its formation?

please help me