As it turns out, the addition of four new teams, the departure of BMW Sauber and a massive game of musical chairs in the driver's market aren't the only big changes in store next year in Formula One. As this year's championship winds to a close, reports emerge that several teams are switching their engine partners for next year.

Following earlier reports that McLaren could fully divorce from Mercedes and acquire arch-rival BMW's engine operations, new reports indicate that both Red Bull and Williams are switching engine suppliers for the upcoming season. Williams announced a couple of weeks ago that it was terminating its deal with Toyota early due to dissatisfaction with the performance of the Japanese engine package. While the independent British team had reportedly been negotiating with Renault, inside information now indicates that Williams will take advantage of the new Cosworth package for next season instead.

Meanwhile, Red Bull could end up with the Cosworth package as well. The team has revealed that it is considering staying with Renault or alternatively switching to either Mercedes, Toyota or Cosworth. Unsatisfied with the Renault package and with McLaren reportedly vetoing RBR's tie-in with Mercedes, it's now apparently down to Toyota and Cosworth. Insiders point out that with the ban on engine development still in place for the returning manufacturers, Cosworth is the only provider capable of developing a new engine.

The two veteran teams would be joining Manor, Campos, Lotus and USF1 under Cosworth power. Ferrari, Renault and Toyota will, of course, continue building their own engines. If McLaren doesn't absorb BMW's engine department in time, it will likely stick with Mercedes, while Brawn and Force India are expected to continue with Mercedes power as well. That leaves Toro Rosso, which has yet to confirm if it will continue using Ferrari engines as it has for the past three seasons.

[Sources: Autosport and F1-Live]