* Steinhoff says to place around 29.5 mln shares in PSG
* Shares to be placed in accelerated bookbuilding
* Move comes as Steinhoff seeks to plug liquidity gap
* Johannesburg bourse says may suspend trade in Steinhoff debt (Adds bonds may be suspended on JSE)
FRANKFURT, Jan 22 (Reuters) - South African retailer Steinhoff plans to sell about 7.5 billion rand ($620 million) of shares in investment firm PSG Group as it scrambles to plug a liquidity gap after it disclosed "accounting irregularities".
In a separate development, South Africa's bourse said on Monday it may suspend trade in Steinhoff bonds if the company's delayed financial results are not published before the end of February, which could complicate efforts to raise fresh debt.
The group, which owns more than 40 brands, such as Conforama, Mattress Firm and Poundland, said on Monday it would place around 29.5 million shares in PSG with institutional investors in an accelerated bookbuild. Steinhoff owns 16 percent of PSG, which has a total market value of around 60 billion rand.
Steinhoff last month shocked investors with the disclosure of what it said were irregularities in its accounts, wiping about $15 billion, or 85 percent, off its market value as it delayed its results.
However, it said in a statement on Monday the placement would only go ahead if it achieved acceptable pricing. "Steinhoff will not dispose of the Placing Shares at all costs, as the Placing is being undertaken in order to be pro-active and prudent," it said.
Steinhoff's top two executives have resigned, as well as its chairman, and the group is currently being run by an acting chief executive while its former finance chief works full-time on securing financing.
Sources familiar with the matter had told Reuters last month that Steinhoff was considering selling stakes worth a combined $1.4 billion in PSG Group and KAP Industrial to raise much-needed funds.
Steinhoff owns 39 percent of diversified industrial group KAP, which is worth around 22.4 billion rand at current market prices.
PSG Capital Proprietary Limited and The Standard Bank of South Africa Limited are acting as joint bookrunners for the placement in PSG shares.
Steinhoff faces new challenges on the debt front. Andre Visser, the General Manager of Issuer Regulation, said in an emailed response to Reuters queries that the exchange could suspend trade in the company's bonds over the results delay.
"In terms of the debt listings requirements, they have until 31 January to publish their year-end results. The requirement then provides issuers with an extra month grace period. Failure to publish by the end of February could result in suspension," Visser said.
Steinhoff Services Limited is the issuer of the company's debt and the Business Day newspaper reported on Monday that Steinhoff had 11 bonds listed in Johannesburg with an outstanding value of 6.8 billion rand.
($1 = 12.0875 rand) (Reporting by Maria Sheahan; Additional reporting by Ed Stoddard in Johannesburg; Editing by Kenneth Maxwell and Louise Heavens)