At the same time, it was rumoured that 23-year-old Danish rookie Sorensen will almost certainly be Valsecchi's successor.
He raced in Lotus' black and gold colours in the Formula Renault 3.5 series last year, finishing seventh, and in September made his F1 test debut in a two-year-old car at the Paul Ricard track.
Valsecchi met with Lotus' departing chief executive Patrick Louis last week, and before the meeting speculated to f1passion.it: "Maybe he wants to wish me a happy new year, or tell me that he is resigning, or that they have hired Sorensen."
The latter is probably the truth.
Lotus announced on Monday that it has signed online Danish investment bank Saxo Bank as a new sponsor.
The bank is perhaps best known for its title sponsorships at the highest level of professional cycling, including the current Tinkoff-Saxo team.
"Saxo Bank is excited to have the opportunity to diversify its sporting partnerships, which now forge close ties to two of the world's most popular sports," co-CEOs and founders Kim Fournais and Lars Seier Christensen said in a statement.