LONDON (Reuters) - Max Chilton will be the fourth British driver on the Formula One starting grid next season after back-markers Marussia said the 21-year-old would make his race debut with them.

Chilton, this year's reserve driver, will partner Germany's Timo Glock at the Russian-licensed team who have yet to score a point.

"It's hard to put into words how I'm feeling today, with the announcement that I will be racing for the Marussia F1 Team in 2013," said Chilton in a statement.

"I am very fortunate to have spent the last six races with the Marussia F1 Team as reserve driver, which means that instead of a standing start, I am already up to speed and at ease with the people, the culture, the systems and of course, the 2012 package."

(Reporting by Alan Baldwin, editing by...)