The Financial Times is automatically warning its journalists if their articles quote too many men, in an attempt to force writers to look for expert women to include in their pieces.

The media organisation found that only 21% of people quoted in the FT were women, prompting the development of a bot that uses pronouns and analysis of first names to determine whether a source is male or a female. Section editors will then be alerted if they are not doing enough to feature women in their stories.

The paper, which covers many male-dominated industries, is keen to attract more women readers, with its research suggesting they are put off by articles that rely heavily on quotes from men.

Staff were told that, in future, automatic textual analysis could warn FT journalists about the lack of female voices in an article as it is being typed.

A separate experiment to ensure more images of women are used to illustrate FT articles has shown “women are more likely than men to click through on a picture of a woman and less likely than men to click through on a picture containing only men”.

“Desks that use quotes from a high proportion of women also feature more women in their pictures, and their articles are well read by women,” the deputy editor, Roula Khalaf, told staff in an internal email, saying that women tend to feature in stories about the NHS, US immigration, and EU tech regulation but less so in stories about US trade, the oil industry and banking.

She also said the proportion of female opinion writers on the newspaper increased from 20% to 30% between March and August.

“The opinion desk is tracking not only the gender of contributors, but also their ethnicity and geographical location, as part of an effort to commission more female voices, more minority voices in western countries and more local voices elsewhere.”

The development comes as newsroom sources claim the FT’s news editor, Peter Spiegel, is being lined up to become the US managing editor early next year, replacing Gillian Tett.

Tett, who is thought to have put up some resistance to the move, is expected to remain in the US and take up a role looking after the FT’s editorials. The paper’s executives are jostling for position in the eventuality that the current editor Lionel Barber – who has been in the job since 2005 – chooses to step down. An FT spokesperson declined to comment on speculation.