Uber Technologies Inc. won a probationary license to operate in London on Tuesday in a partial victory for its new chief executive after it made changes to ease strained relations with city authorities.

The new license was subject to strict conditions, however, and came with a warning to prove it had changed to retain its right to operate in London, the heart of its biggest European market.

Uber overhauled its policies and personnel in Britain after Transport for London (TfL) refused to renew its license in September for failings in its approach to reporting serious criminal offenses and background checks on drivers.