Sebastian Vettel is close to agreeing a contract extension with Red Bull.

That is the claim of Germany’s Sport Bild, reporting that the reigning world champion will sign up through 2014.

Currently, the 23-year-old’s deal is set to expire at the end of this season, even though an ’option’ is expected to also keep him with the Milton Keynes based team in 2012.

But team boss Christian Horner and owner Dietrich Mateschitz - although binding Mark Webber for the 2011 season only - have expressed eagerness to keep Vettel for a much longer term.

The 2010 title winner has recently been musing a future switch to grandees Ferrari or Mercedes, but Sport Bild said Red Bull is offering him a new retainer of EUR 10 million per year.

The German newspaper Bild said the figure is closer to 12m per year.

The report also said Vettel will be given more free time, for example by limiting his PR appearances.

Sport Bild said the deal could be announced mid next week.

Dr Helmut Marko confirmed the talks: "We are in the talking phase and nothing is signed yet. It’s going to take some time yet."

It is also expected that Adrian Newey will stay at Red Bull until at least 2014.

"We have bound until and including 2014 all of our most important pillars," Marko added.

Meanwhile in Barcelona, the last test day of the 2011 pre-season for Ferrari, McLaren, Williams and Mercedes is close to a complete wash-out.

It has rained too much even for meaningful wet-tyre testing "and there is no sign of improvement on the horizon", said Ferrari.