Colin Gibson, the chief operating officer at Your Legal Friend, said: "This letter of claim is the next significant step towards shareholders recovering compensation for their investment losses.
Within a week of my own firm, Bhatt Murphy, being instructed, a 17-page letter of claim was provided to the CPS and police.
We have sent a letter of claim, it is eight pages long, which sets out why it is an unreasonable intervention at this stage".
Your Legal Friend has sent a letter of claim to the company on behalf of 342 retail investors initially, warning that the number could rise as it has been contacted by more than 1,100 so far.
Speaking to The Telegraph, law firm Unity Law said it has been instructed to send a letter of claim to the university, setting out a challenge for disability discrimination, a breach of the equalities act and a failure to make reasonable adjustments on the grounds of disability.
A letter of claim sent to the MoD says the claim is based in part on "the army's knowledge of and facilitation of the shipment", while one sent to the Police Service of Northern Ireland says the claim arises from a series of failings, including "closing off investigative opportunities" and "the destruction of vital evidence".
PC Rowland issued a letter of claim against Mr Mitchell, on Tuesday, in the wake of their differing accounts of what happened in Downing Street in September 2012.
A Police Federation spokesman said: "We can confirm that PC Toby Rowland yesterday issued a letter of claim for libel against Andrew Mitchell MP.
Mr Belhadj's lawyers said their letter of claim against Jack Straw relied on the same allegations and evidence set out in the letters to Sir Mark and the government.
With our letter of claim, we sent SoundCloud a list of 4,500 musical works which are being made available on the service, as a sample of our repertoire being used, so that they understood the scale of our members' repertoire and its use on the service.
