March 27 (Reuters) - Top fashion retailers ASOS , Boohoo and George at Asda have signed undertakings to clarify the way they display, describe and promote their environmental credentials, Britain's competition watchdog said on Wednesday.

The announcement follows a 2022 investigation by the Competition and Markets Authority (CMA) amid heightened scrutiny of companies exaggerating their green credentials in an attempt to woo climate-conscious consumers as well as billions of dollars from environmentally focused investor funds.

Some of the undertakings include making clear statements about materials used in green ranges such as 'organic' or 'recycled' instead of 'eco' or 'sustainable' and setting out clear criteria to decide which products are part of the environmental collections, the CMA said.

The three brands together make over 4.4 billion pounds ($5.56 billion) annually from UK fashion sales alone, according to the regulator.

($1 = 0.7920 pounds) (Reporting by Eva Mathews in Bengaluru; Editing by Savio D'Souza and Sohini Goswami)