May 1 (Reuters) - British luxury carmaker Aston Martin posted a bigger-than-expected first-quarter pretax loss on Wednesday due to higher finance costs and the timings of its car launches.

The company reported an adjusted pretax losses of 111 million pounds ($138.45 million) for the three months ended March 31, compared with 57 million pounds a year earlier.

Analysts, on average, were expecting an adjusted pre-tax loss of 93 million pounds, according to a company-compiled consensus.

($1 = 0.8017 pounds) (Reporting by Yadarisa Shabong in Bengaluru; Editing by Sherry Jacob-Phillips)