General Motors Co and Ford Motor Co, the two largest US automakers, have agreed to jointly develop a new line of nine- and ten-speed automatic transmissions to boost the fuel economy and performance of their lineup, the companies said on Monday.

The pact marks the third time in the last decade that the two automakers have collaborated on transmissions. The joint effort allows GM and Ford to bring the transmissions to market more quickly and at a lower cost than if they worked alone.

GM and Ford will build both front- and rear-wheel drive transmissions as part of this effort. Engineering teams for both companies have already started initial design work.

The US auto industry is scrambling to find ways to boost fuel economy by 2025, when US government standards mandate that automakers show a corporate average fuel economy of 54.5 miles per gallon (23.2 km per liter).

That translates to about 39 mpg in real world driving, or nearly two thirds higher than the average fuel economy for the 2012 model year vehicles. The Environmental Protection Agency projects that, on average, 2012 vehicles got around 23.8 mpg.