She joined last week and replaced Live head Christian Mahne, who has left the agency to work independently.
Cooper was most recently a senior broadcaster at the BBC World Service for eight years, working on the station's flagship international and European business programmes. Prior to that, she spent two years as a presenter/reporter for financial TV service The Money Channel.
She also spent seven years at Goldman Sachs, where she became an executive director in equity research sales.
Lansons' co-founder Tony Langham said: 'Louise's deep understanding of the City and investment management world gives us a great chance of generating Lansons Live business in those sectors.'
She joins as an associate director and will head the Lansons Live team and oversee a review of the division.
This will encompass its broadcast PR capability, media trading, film making and how the agency markets its studio for hire to other broadcasters.
Cooper commented: 'Broadcast has become a vital tool for the comms industry.
'Lansons Live is well established now, so the task is to look at the business and see where its core strengths can be best used.'
She added: 'There is a great deal of work to be done in explaining to firms how they can get the most out of broadcast, as it is an area that remains widely misunderstood.'
Langham said that once Cooper had completed the review of Lansons Live she would help the firm expand its City PR capability.
As part of the move, Lansons' head of digital, Simon Sanders, has moved from Lansons Live back into Lansons itself.