At the start of the 1990s, McLaren continued to dominate the sport with Ayrton Senna taking back-to-back titles in 1990 and 1991. McLaren signed the promising newcomer Mika Häkkinen as a test driver at the end of 1992, but by 1992 Williams was once more in the ascendancy. McLaren was not to win another title for seven years. With the loss of Honda power in 1993, Dennis was left haggling with Ford and Ford's works team Benetton for a supply of competitive engines. A disappointing partnership with Peugeot in 1994 failed to yield the expected results and left Dennis searching to find a fourth engine partner in as many years. In October 1994 he agreed terms with Mercedes-Benz to supply engines from 1995 onwards, an association that continued until 2014.